Bought a cmmg Banshee in 10mm. Thus far I love it, but I'm getting brass bulges unlike any other 10mm I've shot.
Spent brass sometimes looks like a pear. Exaggeration...but the expansion at the case head can be dramatic.
Some of my reloads are really impressive, but I'll stick to factory brass to reduce confusion.
Federal Premium 180 grain Trophy Bonded, factory new:
4,800 MSL
36 degrees Farahenite
Average velocity 1,407 from the 8" Banshee barrel.
Largest case bulge: .4390
I run every case I shoot through a Lee Bulge Buster prior to reloading, and even with the cases that don't want to go through after being fired, I can't actually see any deformation. The cases from the Banshee...I can see the distortion before I even bend down to pick them up. They look like a belted magnum.
This is not a "Glock bulge" where it only occurs at the unsupported portion of the chamber, but a consistent "ring" around the base of the spent brass.
I just don't know what to make of it. Some of my reloads bulge out to .4655". Granted they're reloads in mixed brass loaded to book-max, but WOW...that's a lot of bulge!
The same batch of Federal Trophy Bonded showed ZERO case bulge out of my KKM barrel in a Glock 20, so I don't think it's a hot batch of ammo.
Any ideas?
Sounds excessive bulges IMO... and that's from a G20 ( which is known to be loose ) reloader that sometimes goes max...reloads bulge out to .4655
Usu I don't get more than .433 in any loadings and .434 is my cut off ( from past info here )
Honestly only see the .434 when copying some of the Buffalo bore's loadings which are hot.
Have you measured the chamber ? .. is it just looser then normal ?
Might be a timing problem. Action could be opening before the pressure drops enough. I've seen a few reports of 10mm AR attempts that sheared their brass and left the top half of the case in the chamber.
This has been covered on other boards. Here's the CMMG official response:
CMMG recognizes that the chamber lead and chamber in the Mk10 result in a less than 100% fully supported casing. Handguns do not have the same lead or chamber design due to the short distance and the way the round chambers with the barrels tipping/moving to assist, yet many 10mm handguns have unsupported cases also. The Mk10 chamber and lead were designed in a way to provide the most reliable feeding behavior while maintaining safe operation with properly loaded 10mm ammunition. The chamber and leads used to manufacture the Mk10 are similar to those we use on the 9mm, 40S&W, and .45ACP. With these calibers we do not see any bulging with any factory offerings of +P or below ammunition. Unfortunately, 10mm was designed in a way that pressures generated by max loads cannot be well contained in an unsupported chamber, resulting in case swelling and the inability to reload cases with certain combinations. Not every 10mm case is the same. SAAMI only defines the external dimensions of cases, which leads to varying wall thicknesses and strength. We've measured as much as a 25% difference in wall thickness between manufacturers.
CMMG has fired tens of thousands of rounds through our durability testing and found no safety concerns from the case swelling. During our function and reliability testing, which tests feeding, extraction, ejection, and durability, we tested a wide variety of ammunition. We found that when the Power Factor > 230, using 180gr bullets, the greater the likelihood the casing will show visible signs of "bulging". CMMG concluded that the firearm was still safe, as it is designed to function and contain the pressures of properly loaded 10mm ammunition safely. CMMG does not recommend continuing to shoot ammunition that shows multiple signs of overpressure. If you are seeing extreme case swelling and any other common sign of overpressure, such as ejector swipes, blown primers, split cases, etc., discontinue using that ammunition and test another load or brand. CMMG stands behinds its products and is confident in our design of safe and functional firearms. In this case, we have found the inherent design of the 10mm cartridge produces some tradeoffs when it comes to the ability to reuse and reload cases. Once again, we would like to thank you for your business and hopefully this brief explanation might help you better understand our position on this particular situation.
Quote from: PointBlank82 on February 17 2020 05:13:10 PM MST
This has been covered on other boards. Here's the CMMG official response:
CMMG recognizes that the chamber lead and chamber in the Mk10 result in a less than 100% fully supported casing. Handguns do not have the same lead or chamber design due to the short distance and the way the round chambers with the barrels tipping/moving to assist, yet many 10mm handguns have unsupported cases also. The Mk10 chamber and lead were designed in a way to provide the most reliable feeding behavior while maintaining safe operation with properly loaded 10mm ammunition. The chamber and leads used to manufacture the Mk10 are similar to those we use on the 9mm, 40S&W, and .45ACP. With these calibers we do not see any bulging with any factory offerings of +P or below ammunition. Unfortunately, 10mm was designed in a way that pressures generated by max loads cannot be well contained in an unsupported chamber, resulting in case swelling and the inability to reload cases with certain combinations. Not every 10mm case is the same. SAAMI only defines the external dimensions of cases, which leads to varying wall thicknesses and strength. We've measured as much as a 25% difference in wall thickness between manufacturers.
CMMG has fired tens of thousands of rounds through our durability testing and found no safety concerns from the case swelling. During our function and reliability testing, which tests feeding, extraction, ejection, and durability, we tested a wide variety of ammunition. We found that when the Power Factor > 230, using 180gr bullets, the greater the likelihood the casing will show visible signs of "bulging". CMMG concluded that the firearm was still safe, as it is designed to function and contain the pressures of properly loaded 10mm ammunition safely. CMMG does not recommend continuing to shoot ammunition that shows multiple signs of overpressure. If you are seeing extreme case swelling and any other common sign of overpressure, such as ejector swipes, blown primers, split cases, etc., discontinue using that ammunition and test another load or brand. CMMG stands behinds its products and is confident in our design of safe and functional firearms. In this case, we have found the inherent design of the 10mm cartridge produces some tradeoffs when it comes to the ability to reuse and reload cases. Once again, we would like to thank you for your business and hopefully this brief explanation might help you better understand our position on this particular situation.
I was really looking forward to buying one of these, but looks like I'll be sticking with my MechTech for now.
I started to write a reply to this twice last night and stopped as I thought it wouldn't pertain to OP's question/concerns.. that seems to have been addressed.
Now I have several 10mm pistols and I just finished a Carbine as a Valentine's Day gift to myself. It's still in the T&E phases and I will make a detailed post about the build and my experiences when I gather more data. I handload and absolutely Love messing around with everything the 10 has to offer. I've only got a chance to bring it out twice in the last few days.. tomorrow if we get rained out at work will be a third. :)
I tried some of my hot hand loads that run in my over sprung (34# mainspring) compensated beast of a test bed 1911 after running through initial tests/barrel break in.. I have brought the brass to the failure point without any sort of out of battery detonations or insane case head expansion.. Nothing over .428 and that is in a KVP 16" 1:16 Barrel that I ramped and polished for ultimate reliability in feeding everything and boy does it eat it all up! I was in no way concerned of case "smiley" bulges as two of my 1911's have just about the same case head exposure.. and I have never had a problem with hot loads of NO.9, 800x, LS, PP.. you name it.
As for graybeards statement about 10mm AR's ripping brass in half on its way out.. well I shot some 165's 11.2 LS 1.255" qL says " 11.20 1708 fps 1071 ft lbs 48177 psi 100.0 burn % !DANGEROUS LOAD-DO NOT USE!" Proofs being 30% over SAAMI max on case pressure.. 48,750 BRASS FAILURE!
I had case failures every couple of rounds and would have to pop her open and take out the half a case from the chamber.. Not an issue and I have a little rubber plunger I happened upon that makes it a breeze..
My numbers
1620,1633,1645,1663,1629,1657,1639,1641,1650,1654,1657,1639,1671,1661,1683,1689,1671,1658,
1657 Average 1653.5 SD 17.8 HI 1689 LOW 1620
That's 1,001 ft lbs. avg. boys.
I sighted in my HS503CU at 41yds and using the 2moa dot as a hold over (as per quicktargets ballistics) was smashing clay pigeons on the 100yd backstop. Nothing but smiles. I have a to say I am thrilled and although there is more testing for me to do, However I am glad I went the route I did and skipped the CMMG. Blowback 10's can be done.. I set out on a mission and I feel I accomplished it @ 34.62oz bolt/buffer combo.. I used this (https://10mmautocombat.wordpress.com/blowback-bolt-calculations/) as a general guide line, call it hog wash if you will but it seemed to have worked for me.. to the point of no out of batteries with 600rds down the tube. 48,800psi/44.8oz = 1089.285714285714 PSI per OZ = 37,711 PSI
8" Banshee weighs 5lbs 10oz or so they say there info seems wacky My 16" 7lbs with Holosun. $1,500 case, optic, 7 - 30rd mags, speedloader :) and sling puts it right there with the CMMG as well.
Muskrat I'm sorry to hear about the bad bulges and what seems to be a lack of a resolution other than maybe a new barrel?? I never inquired much with CMMG but is there radial de-layed bolt and barrel of a proprietary design? I would think so.. :( If you intend to keep it I would begin the long and arduous task of finding what combination of brass, powder, and bullets give you the best results as far as not having such badly bulged brass.. Have you tried BulgeBusting or G-RX'ing the banshee brass? Or are they simply a no go? Total loss? They say there's no free lunch with physics but it kinda sucks that CMMG doesn't just readily state "Hey this gun will cycle and safely shoot all factory and Hotter 10mm..Just Don't plan on reloading it!
I'm glad to have found this forum full of 10mm nuts! I've been a long time outside observer.. but I finally decided maybe I could throw my two cents out there. -Ben
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Thanks for the help everyone!
I haven't heard back from CMMG due to the long weekend, but I suppose the above post is a spoiler as to their response.
So with about 500 rounds through the Banshee, here's what I've noticed:
No malfunctions, failure to feed, or failure of the bolt to lock open on the last round, even with stock Glock magazines.
It's accurate...I'm the weak link near as I can tell.
Recoil is negligible. I shot some of my 200 grain, 1,100 fps target loads with the brace against my chin. Didn't love it, but it didn't really hurt, either.
It eats everything I've thrown at it, from vintage Underwood 200's (1350 fps from the 8" Banshee barrel) to my hot reloads to my powder-puff target reloads and any and all random factory ammo I had laying around. It has functioned perfectly with everything from 226 grains to 135 grains, all loaded from hot to tepid.
Book-max or Super-max loads run fine, but the brass goes in the dumpster. I'm not sure that's a terrible thing...I've had problems reloading spent brass from Underwood or my own semi-nuclear loads, mostly gas cutting around the primers. I think that reloading spent brass makes sense for a -90% load, not hotter.
I'm currently happy to shoot loads that bulge like the Federal Trophy Bonded 180 grain...once. I'm a little bummed about the single-use of brass, but then again I rarely reload or even shoot hot loads. I seen no point in pushing a 180 grain slug to 1,400+fps just to ring some steel. It's a nice field round, but I don't need to reload it...won't go through 100 in a year so no big expense to throw the brass away.
My typical plinker/target load is a 200 grain Blue Bullet going about 1,090 fps from a 6" kkm barrel. The 8" Banshee barrel kicks it up another 50~70fps, an NO bulges in multi-reloaded, mixed brass.
The Banshee is freaking FUN! It's a stupid gun for me in a lot of ways...not the least being that I can't shoot USPSA with it unless I convert it to a SBR and accept all the associated costs and restrictions. But it's the only...er...10mm that can be shot from the shoulder if need be...that runs whatever load you put through it. I just can't abide a finicky gun...no attribute makes up for it in my mind. If there was another reliable 10mm carbine out there I'd have gone that direction, but I never found one.
I might eventually get a second lower and register that as a SBR so I can shoot USPSA...or not. I bought it figuring that if I was bored with it in a year I'd just sell it.
Quote from: BENTENMM on February 17 2020 06:03:42 PM MST
As for graybeards statement about 10mm AR's ripping brass in half on its way out.. well I shot some 165's 11.2 LS 1.255" qL says " 11.20 1708 fps 1071 ft lbs 48177 psi 100.0 burn % !DANGEROUS LOAD-DO NOT USE!" Proofs being 30% over SAAMI max on case pressure.. 48,750 BRASS FAILURE!
I had case failures every couple of rounds and would have to pop her open and take out the half a case from the chamber.. Not an issue and I have a little rubber plunger I happened upon that makes it a breeze..
I'm not sure I know what your point is here. Overpressure loads cause case failure? I did a fair amount of research before I got my 10mm AR. There are several threads on other forums about 10mm carbines shearing (not ripping) their brass. They were leaving about half of the case in the chamber and, of course, jamming up. It was a timing issue.
Given the range of power levels in 10mm ammo and the fact that the Banshee uses a delayed blowback system, am I being stupid in thinking that the action could possibly be opening a little early with hot loads and reducing case head support?
I'm sorry for the confusing statements I made. I was in a way I guess trying to elaborate the only times I experienced case shearing or failures were in extremely over pressured rounds. I don't think that anyone is stupid for taking in account any minute detail that would attribute to a loaded and fired cartridges performance as there are so many factors that can result in such a wide array of outcomes. As pointblank82 posted about the Banshee's chamber lead/support that tommac919 had a suspicion of..
Muskrat please fill us in on any new info you might get from CMMG in response to your inquiry. I don't look at these as stupid or pointless firearms.. They are something we enjoy and if it's what we choose to spend our time & money on then so be it.. people have lots of different hobby's that to others seem to rather fruitless except for personal gratification. I was at the range one time with some of my favorites and was talking to a fellow firearms enthusiast when I made the statement "yeah I know to a lot of people this is a crazy amount of money to spending on such toys right.." and he replied "you know what I've never seen? Is a Bank truck following a hearse, you can't take it with you and if its what you want in Life and it makes you Happy then does any of it really matter?"
I'd still say the Banshee is a Great purchase and I would have made one myself but I've always been fearful of the pistol brace laws and don't want to SBR.. My 5.56's are 14.5 pinned guns. I almost went that route as BBTI pretty much shows 14" being the optimal 10 barrel length.. Once I have more time with this one, I might make another even smaller.
Thank you to everyone involved in this thread, it's always Good to get a collective together get some thoughts and facts out there for others. -Ben
Quote from: BENTENMM on February 18 2020 10:15:28 AM MST
I'm sorry for the confusing statements I made. I was in a way I guess trying to elaborate the only times I experienced case shearing or failures were in extremely over pressured rounds. I don't think that anyone is stupid for taking in account any minute detail that would attribute to a loaded and fired cartridges performance as there are so many factors that can result in such a wide array of outcomes. As pointblank82 posted about the Banshee's chamber lead/support that tommac919 had a suspicion of..
Muskrat please fill us in on any new info you might get from CMMG in response to your inquiry. I don't look at these as stupid or pointless firearms.. They are something we enjoy and if it's what we choose to spend our time & money on then so be it.. people have lots of different hobby's that to others seem to rather fruitless except for personal gratification. I was at the range one time with some of my favorites and was talking to a fellow firearms enthusiast when I made the statement "yeah I know to a lot of people this is a crazy amount of money to spending on such toys right.." and he replied "you know what I've never seen? Is a Bank truck following a hearse, you can't take it with you and if its what you want in Life and it makes you Happy then does any of it really matter?"
I'd still say the Banshee is a Great purchase and I would have made one myself but I've always been fearful of the pistol brace laws and don't want to SBR.. My 5.56's are 14.5 pinned guns. I almost went that route as BBTI pretty much shows 14" being the optimal 10 barrel length.. Once I have more time with this one, I might make another even smaller.
Thank you to everyone involved in this thread, it's always Good to get a collective together get some thoughts and facts out there for others. -Ben
No worries, I wasn't jumping to offense, just a little confused. As I mentioned earlier, I did a lot of research in my quest for a gas operated AR carbine in 10mm. Lots of reports of guys building their own that were shearing off cases, using factory ammo. Even some of the fairly weak tea, like American Eagle, was doing it. .308 buffers seem to be the answer to that problem.
Others had bigger problems, like this fellow.
https://hosting.photobucket.com/albums/s276/rsvetlik/KABOOM.jpg These are from a brand new Oly 10mm AR, not mine. First round fired and ejected. Second round sheared off and left top part in chamber. Third round partially chambered and fired out of battery. You can actually see where the top of the second round swaged the bullet down and was jammed a little into the rifling. That had to be a new underwear kind of experience with a blowback gun ;)
Thanks for the explanation.--Jim
Yep just picked up my banshee last week and finally had time to go shoot it yesterday. Sonofabitch if i didn't get home and start to deprime/resize brass and literally had to pull my brass out of resizer die with channel locks. i'm like WTF. So I continue to resize/deprime and about every 5 rounds or so same problem. I remember reading on a guys video on the banshee on youboob a guy in the comment section was saying about 6 months back this was an issue however another guy replied cmmg had fixed this. One guy said his wouldn't work at all and sent it in and cmmg said they screwed up and put a .40 bolt in his by mistake.
Anyways, i'm wondering if changing out the bolt, buffer, spring or SOMETHING would alleviate this issue and I already spent $1,200 on this thing. It shoots great, accurate as hell. I already spend a lot on shooting and reloading to my wife's chagrin. It pisses me off to no end that cmmg wouldn't mention something like this. I guess they figure a guy who can spend $1,200 on a gun can spend money on endless amounts of factory ammo and doesn't reload anything so who cares?
On this subject, what is the best brass besides Starline? I have used a ton of S&B brass and it holds up really well to multiple reloads. Strangely enough, NONE of the S&B brass bulged yesterday ONLY the Starline. Anyone ever use Jagemann brass? From what i've seen Jagemann brass is built pretty stout. It seems like S&B quality. I'd buy S&B brass but they only sell it fully factory loaded. Winchester brass sucks for reloading and now Starline seems to be weak sauce but I guess spending $16 for a box of 50 rounds to not only shoot but then save the brass to reload is more economical than paying $20+ for a bag of 100 rounds of brass that I have to prime and put powder and a bullet in.... I've heard quality control at Starline has gone downhill which sucks however i've never had a bulge issue with any of my regular pistol's/1911's with Starline brass....The only problem with S&B brass is the primer pockets are so friggin tight the first couple of reloads when re-primering them. I'm not loading these super hot either. 7 grains of Unique. I did shoot some 7.5 gr Unique's also but it was S&B brass and none of those bulged. Could it be a burn rate thing? Maybe switch powders and spend countless hours working up loads? Ugh this suuuucks...
Lastly, am I going to need to buy a bulge buster die as someone mentioned above if I want to get more reloadings out of my Starline brass or would that even work?
My guess regarding the Banshee is that they utilized a partially supported chamber to increase reliability. If there's a 10mm carbine that also has a fully supported chamber and runs whatever you put through it, I haven't yet heard of it.
I'm also guessing that dedicated Banshee owners will find the sweet spot between velocity and brass damage...maybe you can push a 200 grain bullet to 1150 fps and still reload most of the brass, but at 1225 it all goes in the trash, or something like that.
Since hot-loads and re-used brass have caused me weapon damage in the past due to loose primer cups and gas cutting, I'm not entirely sure that a fully-supported chamber and consequential lack of bulging is doing me any huge favors. Granted, I might feel differently if I hadn't already purchased and gotten to like a Banshee, but I'm not depressed about having to find the sweet spot with reloads that allows me to save the brass, but still shoot something significantly hotter than .40 S&W.
A few months and a couple thousand rounds from now I'll have a more developed opinion, but for now it seems like 10mm carbines and unsupported chambers are synonymous if you want reliability. And, while it's not perfect, I'll take a reliable carbine that destroys the brass over an unreliable carbine that doesn't. YMMV.
On another note...not a word from CMMG in response to my queries. From a customer service perspective, I'm currently not supper-impressed.
Found this on another forum from a guy having the exact same issue's as we are. This is copied exactly from the email CMMG sent to the guy. Enjoy the B.S. ALSO as a note I got ahold of CMMG tech support and physically talked to a guy this very morning 0800 PST and he said brass thickness is the big part of it. He said they reload there and shoot everything thru their guns before they leave and they have found that Hornady brass holds up the best even with nuclear loads. They get an average of 3-4 reloadings with Hornady brass before its bulged to bad so I guess I'm getting Hornady brass and see how that works. I hate Hornady brass for my rifles but maybe for 10mm it's better so hopefully this helps everyone. I asked him if going to a lighter load say 135 gr would alleviate this and maybe a lighter buffer and he said no. Honestly I don't see how it wouldn't fix the issue by going lighter bullet/less powder but he said nope. Just get Hornady brass......Peace!
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Dear Customer,
I am sorry this response has taken so long, but I wanted to ensure due diligence when it comes to the safety of our customers. I personally coordinated testing and validation with CMMG's Product Design Engineers when we received several customers who were concerned with what appears to be 10mm cases bulging. CMMG, Inc. take this very seriously as we had not experienced true case bulging in any of our durability or function testing prior to releasing this firearm. I do want to assure you that the results of the additional testing concern that your Mk10 firearm is safe and reliable. We removed the barrel in question off of your Mk10 and replaced with a new barrel when it arrived. We did our testing using a CMMG owned lower and multiple barrels from different batches. Our initial testing pre-launch focused on big name manufacturers of 10mm ammunition (Winchester, Federal, S&B, Sig, Hornady, etc.) who had offerings in the most common grains, specifically 180gr and 200gr. With this new testing we ordered new lots of ammo from the original test ammo manufacturers and over 20 different types of ammunition from smaller manufacturers, and in offerings outside of the 180gr & 200gr. We created the statement below based on that testing. What you were seeing on the casing was not bulging, but case swell. Bulging would be where the casing grows in length and the material thins in an area, which typically leads to a ruptured case. Case swelling is what happens to all ammunition when it is fired and it forms to the chamber. Due to the design of the 10mm casing many of the cases appear to be bulging due to the brass filling our chamber lead. With our Radial Delayed Blowback (RDB) our bolt is locked into place when the round is fired and the delayed unlocking ensures safe operation. When the brass is manufactured correctly and the loads are not pushes to the hot side, then this case swell into the chamber lead does not appear.
As I stated above, your firearm has been verified as safe. Choosing a US manufacturer of ammunition in the 1,050 1,275fps will minimize the case swelling on the Mk10 10mm. We had concerns about very hot offerings in 10mm from hand loaders and some smaller but reputable manufacturers. The casings we were provided were a mixture of DoubleTap and Sig Sauer. We were not able to replicate the case swelling to match the spent cases provided. If these were reloads, that could account for the amount of swelling. We are including some of our spent cases with the firearm. When the casing is unchanged, but is used to contain 10mm rounds pushing 1,300fps or greater, then our firearm is still safe. The safety comes from being built around the AR platform barrel, barrel extension, bolt, and RDB delayed unlocking. Unfortunately, bad things happen to casings when anyone chooses to push ammunition beyond the design intent of the casing.
CMMG, Inc. Statement:
CMMG recognizes that the chamber lead and chamber in the Mk10 result in a less than 100% fully supported casing. Handguns do not have the same lead or chamber design due to the short distance and the way the round chambers with the barrels tipping/moving to assist, yet many 10mm handguns have unsupported cases also. The Mk10 chamber and lead were designed in a way to provide the most reliable feeding behavior while maintaining safe operation with properly loaded 10mm ammunition. The chamber and leads used to manufacture the Mk10 are similar to those we use on the 9mm, 40S&W, and .45ACP. With these calibers we do not see any bulging with any factory offerings of +P or below ammunition. Unfortunately, 10mm was designed in a way that pressures generated by max loads cannot be well contained in an unsupported chamber, resulting in case swelling and the inability to reload cases with certain combinations. Not every 10mm case is the same. SAAMI only defines the external dimensions of cases, which leads to varying wall thicknesses and strength. We've measured as much as a 25% difference in wall thickness between manufacturers.
CMMG has fired tens of thousands of rounds through our Mk10 platform durability testing and found no safety concerns from the case swelling. During our function and reliability testing, which tests feeding, extraction, ejection, and durability, we tested a wide variety of ammunition. We found that when the Power Factor > 230, using 180gr bullets, the greater the likelihood the casing will show visible signs of "bulging". CMMG concluded that the firearm was still safe, as it is designed to function and contain the pressures of properly loaded 10mm ammunition safely. CMMG does not recommend continuing to shoot ammunition that shows multiple signs of overpressure. If you are seeing extreme case swelling and any other common sign of overpressure, such as ejector swipes, blown primers, split cases, etc., discontinue using that ammunition and test another load or brand. CMMG stands behinds its products and is confident in our design of safe and functional firearms. In this case, we have found the inherent design of the 10mm cartridge produces some tradeoffs when it comes to the ability to reuse and reload cases. Once again, we would like to thank you for your business and hopefully this brief explanation might help you better understand our position on this particular situation.
Thank you for your understanding and patience in this matter. We took this claim very seriously and only had the safety of our customers at heart. Have a terrific New Year and a blessed day.
Good stuff there phaloxx, thanks!
Frankly I'm a lot less disappointed in CMMG for not putting this information front and center than I am with all the people who reviewed the gun (shooting Underwood ammo in many cases) and never mentioned it. You can't tell me NONE of them noticed the brass...it's pretty obvious even before you pick it up off the ground. Since I really don't load or shoot nuclear loads I'd have probably bought it anyway, but it's a rude surprise after the fact.
For giggles I picked one of my more-bulged pieces of reloaded brass. It's a multi-loaded A USA brass that had a max load of Blue Dot under either a 135 or 200 grain slug...don't know which as I was shooting multiple rounds over a chrono and not picking up spent brass until the end. (BTW, 200 grain XTP & 9.4 grains Blue Dot = 1,289 fps. 135 grain Nosler over 12.2 grains Blue Dot = 1,707 from the Banshee)
Case length before firing is unknown, though I've never had any of my brass get long enough to engage the cutters in my Lee Quick Trim Die. I'm guessing it was probably shorter than the standard 0.922".
Primer looks good...no melting or gas cutting.
Swell measures .4425", and extends .2920" from the rim upwards.
Overall length with the swell is 0.9740" prior to resizing.
After resizing and pass-through sizing overall length is 0.9870"
The brass actually looks pretty good at first glance, though under 20x magnification it's obvious that there is a crease above the reformed swell, and what looks suspiciously like the start of a tear along one part of said crease. Needless to say, it's going in the garbage.
Interesting about Hornady brass...I'll try some. I just bought 1K Starline, but it all gets used in the end.
Two Banshee loads that do NOT show any case bulging in multi-loaded, mixed brass:
200 grain Blue Bullet over 11 grains AA#9
High 1170 fps / Average 1143 fps.
200 grain Blue Bullet over 8.5 grains Blue Dot
High 1241 fps / Average 1211 fps.
I'm interested in finding the tipping point for brass bulging, but frankly 200 grains @ 1150 ~ 1200 fps is more than enough of a plinking load for me.
Now to see what I can do with 165 grain bullets...
yep just went to evergladesammo.com and ordered 500 of their 165 jhp's for $75 free shipping. Why not? My carry ammo for my pistols is 165gr anyways so it'll get shot either way. I figure keep the same grains of powder "Unique 7.0 grains" for these as what I loaded my 180gr bullets to will increase velocity obviously but not increase pressure, If anything it'll go down a few thousand pounds. Just wonder if changing out the buffer will also help?
Quote from: phaloxx on February 19 2020 06:44:12 PM MST
yep just went to evergladesammo.com and ordered 500 of their 165 jhp's for $75 free shipping. Why not? My carry ammo for my pistols is 165gr anyways so it'll get shot either way. I figure keep the same grains of powder "Unique 7.0 grains" for these as what I loaded my 180gr bullets to will increase velocity obviously but not increase pressure, If anything it'll go down a few thousand pounds. Just wonder if changing out the buffer will also help?
You lost me there. What exactly are you doing?
What I meant is ALL my practice ammo is 180gr. So I figure I'd try to move down to 165 gr. Keep the same load data as in powder Unique, AA#9 etc but going from 180gr to 165gr bullets might help alleviate bulging. Just a thought. It may not work but I'm kinda dumb so who knows? I figure less mass moving thru the barrel equals less pressure on the case. It may not work but it's what we all do as reloaders is experiment. That's half the fun. Generally as you go lighter in bullet weights you can increase your powder charge. But I'm going to keep the same powder charge but go to a lighter bullet. See if it helps the bulging/swelling on the brass yet maintain accuracy. If not then I'll back off my powder charge or go to a lighter bullet weight. Not sure yet. Clear as mud now?
Ya...makes sense. What you're doing is often cited as a way to turn a USPSA Major load into a USPSA Minor load without having to re-tool the loading press. So under most circumstances it should yield lower pressures and less bulging.
That said, 7 grains of Unique under a 180 grain bullet is a really mellow load. I'd be amazed if you were getting bulging of any consequence with that combo. If you are you might want to look at some other factors...COL maybe?
One full week since I e-mailed CMMG and I still haven't heard anything back from them.
Not impressed with their customer service...not at all. You'd think a $1,650 firearm would be better supported by the company.
You guys already solved the mystery for me and I know what they'll say if they ever do respond, but still...
Disappointing. Especially for a US manufacturer selling high-end guns at boutique prices.
I asked them about use of slower powders like AA#9 a couple weeks back and only got radio silence:
Thanks Bryan. Could you ask your engineers if the power factor recommendation is limited to medium speed powders with a sharp pressure/burn curve, or if the use of slower powders such as AA#9 would allow for higher PF without the swelling issue?
I intend to work up a 200 gr XTP load for hog hunting and would prefer to use full power loads for practice. Target velocity would be around 1250 FPS which would put things at 250 PF. With 3.4" of additional barrel, I think I'll be staying below the maximum charge, perhaps keeping pressures below 35k psig. See attached clip from AA manual.
Alternately, I may use an even slower powder such as Lil'Gun which is used in 300 blackout loading for similar effect.
Best Regards,
XXXXXXX
CMMG got back to me late today...boiler plate as to what has been posted above.
In a separate email I asked a specific question about recoil buffers and I actually got a specific answer back from a real person...9 days later.
I don't mean to rag on CMMG too hard...I genuinely like the Banshee and I'm glad I bought it. I think they should be more responsive to customer inquiries, but they'll either learn or loose customer base, and that eventually effects them much more than me.
Looks to me like email correspondence is a weak (week?) link with CMMG, and if you want to get any information you should call the sales department (they pick up, Technical Services doesn't) and then ask specific questions that sales can't answer...they'll kick you over to technical services and you've got at least a chance of getting a human being on the phone.
Still very disappointed with CMMG customer service, but I do like the gun.
Sad to hear about the customer service. In building my blowback I got an Angstadt arms bolt from Optics Planet for $92! Holy Hell what an experience that was! I ordered 12/26 and got it 2/14! Several screw ups, all of which were theirs. First and Last time ever doing business with that joke of a retailer.
On a lighter and much more exciting note.. I just go an SGM 30rd Mag from cheaper than dirt because they had a $10 off coupon last weekend so it was $13.33 delivered.. I have been using ETS mags which have been great so far.. but I feel like just the couple hundred I've put through 2 I've noticed some wear on the all plastic feed lips and wanted to explore my other options for the future...
Since we're on the topic of the Banshee, reloading, and the fact that SGM Mags ship with the Banshee's. I noticed the SGM Mag can fit Loads with a COL of 1.289-1.290"!?!?
Is this the case that others have experienced? My ETS's jam at 1.264ish.. pretty lame. I've only tried 2 of the 6 ETS I have, I'm not sure about the rest. I would assume since ETS is all plastic and SGM is metal lined like a real Glock Mag they're more spacious. Loading out some of the longer bullets would be nice.. I have the Magpul M118LR mags for my AR .308s so I can load out past 2.80" but they only make it in 25rd, kinda odd. DNR asking me why I need a 25rd mag to target shoot..
Thanks for any info on the mags. -Ben
Ran a hundred 200 grain BB under 11 grains of AA#9 through the Banshee today.
Got four or five bulges from multi-loaded A-USA brass (garbage brass in my experience), but the rest were fine. I was actually considering culling all my A-USA brass a while ago, but I recon I'll keep using it for target loads and culling it as it bulges in the Banshee.
Some of that brass probably has ten or twelve loads through it, so I'd call it worn brass. Actually glad for the excuse to throw some of it away.
That Banshee rock n' rolls like a vintage jukebox...just damn fun. And accurate. And reliable.
I broke down and ordered the 8oz buffer from CMMG at the ridiculous price of $59. There are cheaper 8oz buffers out there, but they are all too long to work in the Banshee. I might have been able to disassemble and weight the light buffer that came with the gun, but the time and effort didn't seem to justify the savings. Don't need the heavy buffer for my normal shooting loads, but my field loads are Underwood 200 or 220 hard-cast, and I'm not keen to batter my gun for the cost of a dinner and beers at the local brew pub.
Ben: The SMG magazine has proven to be very reliable and of high quality. No idea how it works with long loads, as I just load to book lengths.
Quote from: Muskrat on February 22 2020 06:22:05 PM MST
Ran a hundred 200 grain BB under 11 grains of AA#9 through the Banshee today.
Got four or five bulges from multi-loaded A-USA brass (garbage brass in my experience), but the rest were fine. I was actually considering culling all my A-USA brass a while ago, but I recon I'll keep using it for target loads and culling it as it bulges in the Banshee.
Some of that brass probably has ten or twelve loads through it, so I'd call it worn brass. Actually glad for the excuse to throw some of it away.
That Banshee rock n' rolls like a vintage jukebox...just damn fun. And accurate. And reliable.
I broke down and ordered the 8oz buffer from CMMG at the ridiculous price of $59. There are cheaper 8oz buffers out there, but they are all too long to work in the Banshee. I might have been able to disassemble and weight the light buffer that came with the gun, but the time and effort didn't seem to justify the savings. Don't need the heavy buffer for my normal shooting loads, but my field loads are Underwood 200 or 220 hard-cast, and I'm not keen to batter my gun for the cost of a dinner and beers at the local brew pub.
Ben: The SMG magazine has proven to be very reliable and of high quality. No idea how it works with long loads, as I just load to book lengths.
Check this out! Send that cmmg crap back and get this! Should work in ANY AR style platform!! This is one of the cooler things I've seen in awhile. I know other companies have made similar stuff but not this easy to change out weights or this nice....
https://youtu.be/RbNYm0g77qY
That buffer has a maximum weigh of 5.3 ounces, while the heavy Banshee buffer is 8 ounces. The devil's in the details...
Quote from: Muskrat on February 25 2020 08:47:11 AM MST
That buffer has a maximum weigh of 5.3 ounces, while the heavy Banshee buffer is 8 ounces. The devil's in the details...
Damn, well.... so that heavy buffer is supposed to be for high power factors OR if you run suppressed which I never plan on doing. Hmmm I'm wondering if that would alleviate the bulging brass issue. My thought process is with it being forced to push a heavier buffer back that pressure has to go somewhere besides out the barrel and a heavier buffer would actually make brass bulges worse. That's why I'm going down to 165gr bullets. By the way all my Jaggeman brass arrived today. I can tell you this, as I'm running it thru my resizer die before I start loading it up, this stuff is very stout and thick. Working all day in my shop and hopefully can shoot some of this new brass/bullet combo tomm. Will report my findings if I don't blow myself up or catch corona virus between now and then 😉
I don't know if the heavier buffer will affect bulging or not.
It's recommended for loads making 230 PF and above...Underwood, hot Federal offerings, and of course, some reloads.
Loads that make 230 PF are:
165 grains @ 1393 fps
180 grains @ 1277 fps
200 grains @ 1150 fps
220 grains @ 1045 fps
My understanding is that the goal is to increase functional reliability, not to save the brass. I think some of that brass goes in the garbage at the low end, and at the hight end all of it gets thrown away. Underwood 200 grain bullets make 250 PF and the 220 grain bullets make 264 PF, so even with a heavy buffer I don't think the brass is salvageable from the Banshee.
Obviously reduced loads are not going to bulge brass with the regularity of stout offerings, and they even include a reduced weight buffer for people who want to tone it down to .40 S&W levels. I'll be interested to hear what your experiences are with the 165 grain bullets. I shoot a lot of them in my .40 for USPSA, but I haven't loaded any in the 10mm.
Quote from: Muskrat on February 25 2020 12:07:42 PM MST
I don't know if the heavier buffer will affect bulging or not.
It's recommended for loads making 230 PF and above...Underwood, hot Federal offerings, and of course, some reloads.
Loads that make 230 PF are:
165 grains @ 1393 fps
180 grains @ 1277 fps
200 grains @ 1150 fps
220 grains @ 1045 fps
My understanding is that the goal is to increase functional reliability, not to save the brass. I think some of that brass goes in the garbage at the low end, and at the hight end all of it gets thrown away. Underwood 200 grain bullets make 250 PF and the 220 grain bullets make 264 PF, so even with a heavy buffer I don't think the brass is salvageable from the Banshee.
Obviously reduced loads are not going to bulge brass with the regularity of stout offerings, and they even include a reduced weight buffer for people who want to tone it down to .40 S&W levels. I'll be interested to hear what your experiences are with the 165 grain bullets. I shoot a lot of them in my .40 for USPSA, but I haven't loaded any in the 10mm.
Yeah I guess I need to stop thinking about saving brass and focus on fun and reliability. I'll shoot my 1911 more. I know I can save brass from that being fully supported. It's just that damn banshee is sooooo fun to shoot. Oh well. Yeah I'm gonna chronograph these all tomm or Friday but check out jaggeman brass in the meantime. Just from holding it in my hands and looking at this stuff it's friggin stout. It's same price as new starline brass. Wish I had bought some of this sooner cause the case walls and everything are way thicker. Might be able to actually load some nuclear loads with this brass. Later buddy!
Ran a few hundred rounds through the Banshee with the 8oz buffer. It definitely slows the carrier down, but everything ran fine...even powder-puff loads (165 grains @ 1200 fps).
No idea how it affects brass bulging. I got a lot of bulging with A-USA brass, but none with S&B brass shooting 200 grains @ 1200 fps.
Quote from: Muskrat on February 26 2020 06:54:59 PM MST
Ran a few hundred rounds through the Banshee with the 8oz buffer. It definitely slows the carrier down, but everything ran fine...even powder-puff loads (165 grains @ 1200 fps).
No idea how it affects brass bulging. I got a lot of bulging with A-USA brass, but none with S&B brass shooting 200 grains @ 1200 fps.
I'm telling ya that S&B brass is some stout stuff. Order a 100 round bag or 2 of Jaggemann brass stuff to before corona virus shuts down the country!
I just noticed Sootch did a review, seems like he had to wait for his Sample. Unlike the the other Shills that had them 6 months ago :)
Sootch Banshee MK10 Review
https://youtu.be/ghmbx7Np5dY (https://youtu.be/ghmbx7Np5dY)
On his pull-down of the carbine, a little more in-depth than others. I've come to realize a little more of how the thing is assembled, operates, and it brings up a few questions.
What is the total BCG's weight? Does the angled weight int he back of the carrier look to be made tungsten or stainless steel? Any chance anyone knows the weight of it?
How light does the spring on the bolt itself feel? Any known dimensions?
I'm just spit balling some ideas and some possible tweaks that could be made to perhaps offer a little more in the way of controlling un-locking of the bolt.. although just now after re-reading past post's with info from CMMG concerning the chamber lead and chamber itself being partially unsupported I'm not sure that it would help in case bulging.
Adding a stronger spring to the bolt itself to delay unlocking couldn't possible hurt anything or even be considered a modification that would void the warranty. Also checking to see if there could be a possible alternative to a carrier weight, maybe heavier.
Now for a crazy Idea that would most certainly void the warranty and possibly have ill effects. Would be to alter the angle and or length of the locking lugs themselves on the bolt. I would most certainly order another bolt for this.. but theoretically changing the angle or length of the angle would change the timing of the unlocking from the lugs of the barrel. However reducing the OAL of the locking lugs would create a gap in the lock up and could result in VERY negative results.
These are just some random thoughts, I know it all seems crazy, as CMMG has had engineers design the MK10 with 1,000's of hours of work and 10's of thousands of rounds to produce and market what they have deemed most suitable for safety, reliability, and performance.
What are the lengths of the buffers the MK10 uses? Are the standard AR15 Carbine length? since the bolt length itself is essentially the same?
Aside from the random ideas and questions I would like to add that I really am still thoroughly impressed with the design of most all of the system. I wonder if it really does boil down to a chamber lead/chamber dimensions itself.. Perhaps a company down the line or even a custom barrel manufacturer could make one that would offer better support while still utilizing CMMG's radial delayed system.
Best of luck in finding the best brass and optimal loads for these.
Ya... I don't think the bolt opening early is the issue. I think the issue is that the Banshee chamber is not fully supported and even if you locked the bolt in place to make it a single-shot, it'll bulge the brass at a certain pressure.
The (my) Banshee only bulges full-house 10mm loads in good brass, or warm loads in very poor brass. So download a 200 grain slug to 1200 fps out of the Banshee rather than 1275~1350 fps, and you can reload the brass. Folks wanting to be able to reload Underwood-level loads just need to pick a different platform. You can still shoot Underwood-level loads, just not reuse the brass. Or bring it down ten or twelve percent from max and the brass is just fine.
I'm pretty happy with that. I just think CMMG should have be up-front and center with that information rather than dolling it out to customers who buy the gun and then think "WTF!?!" when they collect their brass.
Range report...about 1,000 rounds through it, and the only malfunction was a hand-load that somehow ended up really long. I'm not getting any bulging from well used S&B or Starline brass pushing 200 grain bullets to 1210 fps, or 165 grain bullets to 1420 fps. If that isn't enough plinking-power then I'd recommend the .458 Socom chambering...
165 grain Blue Bullet over 9.7 grains of Power Pistol clocks in at 1421 fps and is FREAKISHLY accurate from my gun...20 rounds into a quarter-sized hole at 30 yards, without really trying very hard to keep them tight.
This isn't the gun for everyone, but if you want one and are worried that it's a brass-eater, it's not, or at least it doesn't have to be...you just need to choose how you feed it.
I actually want to order one. Bummer is all our ranges are closed due to C-19. Ugg....
So any more teething issues? What are they selling for at retail? TIA
I don't think that your going to find "a deal" on 1, especially right now. When I bought mine about a yr ago, I think all my searching netted me $150 or so off retail.
I enjoy mine.
S&B is pretty much all that I run because its the best combo of affordable and better than 40 while still be "10mm" level.
Quote from: terdog on April 27 2020 10:25:14 AM MDT
I don't think that your going to find "a deal" on 1, especially right now. When I bought mine about a yr ago, I think all my searching netted me $150 or so off retail.
I enjoy mine.
S&B is pretty much all that I run because its the best combo of affordable and better than 40 while still be "10mm" level.
Thanks. Not looking for some killer deal, let me talk to my FFL's in my area - just didn't want to find out they are asking some stupid above retail price.
I'm buying a used 10mm Banshee 300 tomorrow and intend to try some loads with AA#9 and the new AA#11FS to keep the pressures down. Will let you all know what I see.
Will try 180 gr pulled FMJs and some 220 gr Plated RN. Maybe some 200 XTPs one I dial things in.
I think they key for this gun is to avoid the peak pressures you get with the medium speed powders and use better brass. I scored 3k 10mm mixed brass for $265 shipped so will sort out all the A brass and stick with S&B for these trials. I have a shitload of virgin Starline too.
So I've run a bunch of reloads thru my Banshee, 300 180 gr FMJ over 8.5 gr LS w/ CCI #300 and #350 primers. Brass has a minor bulge, but nothing my standard dillon dies cant iron out.
The 9.5 gr LS loads wreck the brass for sure and send them into Canada. I have an 8oz buffer on order from CMMG that might help with full power loads. Recoil difference is negligible as the compensator likes the extra gas.
The 8oz buffer might help you collect some brass, but I don't think it does anything for the bulge. Near as I can tell the bulge happens with the bolt full-closed, and early opening isn't the issue. I think there's just that much unsupported area around the case head with the bolt closed.
The heavy buffer probably does help reduce case separation with full power loads, as the brass has a chance to constrict a bit before the carrier starts moving. I've read about hot loads separating in the Banshee, but I've never experienced it...despite running Underwood and full-house Federal loads through the gun.
I'm pretty happy with the set up, all in all. The Banshee is basically a toy, so 80% loads are fine for shits n' grins, and you can reload them all day long. If you want to shoot full-power or nuclear loads, you just have to discard the brass. In exchange for that you get a platform that will run any-n-all 10mm loads with the monotonous regularity of an atomic clock. So far as I've heard, it's the only 10mm pistol-carbine that even comes close to achieving that.
I still want to score fifty 10mm Magnum brass to cut down for the Banshee. Might work better...might not.
Great toy though...the fact that it runs every cartridge, day-in and day-out, is what I love about it. I just won't tolerate a finicky repeating firearm, and especially not a automatic. If I can't just grab a box of any ammo in my trunk, then load the magazine and shoot, the gun is worthless to me. The Banshee makes the cut.
Well fellas I had a chance to run some reloads through my Banshee and record velocity, case bulge diameter, and accuracy to start a little database of info here to see if we can find that sweet spot for each bullet weight to where the case bulging just gets to be a bit much in our guns.
I tested Longshot, 800x, Blue Dot, and BE-86. Started with starting level loads and stepped up to .3 increase from starting to see where we stood before going any higher. Also fired some factory rounds for accuracy and testing case bulge. Here is a quick rundown of my range testing:
Pistol: CMMG Banshee Mk10 300
Sights: Midwest Industries base mount and Trijicon MRO 2MOA RD sight
Range: All accuary tests below were shot at 25yds except for the last 2 factory loads were shot at 100yds for POI testing.
Cases: FC (All cases were from an original batch of "FBI" loads from years ago)
Primer: Win WLP
Bullet: 180gr CMJ Hollowpoint
COAL: 1.252"
Factory: 180gr SIG Performance Elite for initial sight in and shot a 3 shot group. These were the first rounds from a completely cold weapon on a hot NC day. 90F and probably 70% humidity.
Velocity: Avg=1241fps 1156,1259,1271,1262, & 1259
Accuracy: 1/2 to 5/8" 3 shot group.
Case Bulge Diameter: didn't record it but visual inspection when picking up brass didn't give any excessive alarms.
BE-86:
==========
Wgt: 7.7gr
Velocity: Avg=1265 1277,1273,1275,1270,1229
Accuracy: .688" for all 5 shots
Case Bulge Diameter: .4305"
Wgt: 8.0gr
Velocity: Avg=1271 1268,1257,1270,1273,1287
Accuracy: 1.120" for all 5 shots
Case Bulge Diameter: .4315"
LongShot:
==========
Wgt: 8.5gr
Velocity: Avg=1176 1181,1169,1197,1162,1172
Accuracy: 1.430" for all 5 shots
Case Bulge Diameter: .430"
Wgt: 8.8gr
Velocity: Avg=1241 1217,1244,1246,1237,1263
Accuracy: 1.170" for all 5 shots
Case Bulge Diameter: .431"
800X:
==========
Wgt: 8.5gr
Velocity: Avg=1267 1252,1266,1331,1268,1218
Accuracy: 1.250" for all 5 shots
Case Bulge Diameter: .430"
Wgt: 8.8gr
Velocity: Avg=1326 1319,1338,1337,1315,1321
Accuracy: 1.040" for all 5 shots (1 loose shot, 4 shots =.700"
Case Bulge Diameter: .432"
Blue Dot:
==========
Wgt: 9.8gr
Velocity: Avg=1134 1163,1132,1136,1106,1131
Accuracy: 1.530" for all 5 shots
Case Bulge Diameter: .4305"
Wgt: 10.2gr
Velocity: Avg=1175 1173,1197,1162,1180,1164
Accuracy: 1.750" for all 5 shots
Case Bulge Diameter: .431"
Hornady Custom 180gr XTP Factory
100yd POI testing
4" high at 100yds from 25yd zero of SIG 180gr Elite ammo. So this is hotter than the SIG stuff
Accuracy: 3 3/8" 5 shots
Case Bulge Diameter: .440 to .454"!!!!! these cases were scary to pickup and look at
SIG Performance Elite 180gr FMJ Factory
100yd POI testing
Dead on at 100yds from 25yd zero of this ammo.
Accuracy: 9 1/4" 5 shots (9 1/4" wide and 2 1/4" tall)
Case Bulge Diameter: .435"
These rounds were fired in this order and the gun wasn't cooled off or nothing between groups. So by the time I got to the 100yd impact testing the weapon was very hot to the touch. I wonder if the Hornady 180gr XTP factory loads would bulge that much if fired in a completely cold weapon? Future experiment there. I didn't have velocity numbers for the 100yd testing because I had to swing over for the 100yd burm and didn't move my chrono over and set it back up.
Hope this helps. Will post more data as I shoot this thing more. BE-86 right now is giving we very good raw accuracy. But the heavier 800X charge just might be telling me something. Blue Dot isn't even in the ballpark. Plus I don't know the characteristics of this gun yet to know if it starts walking when hot, how this RD MRO sight is for repeatability etc. I might transfer the 1.25-4x Leupold scope from my AR over to this platform for some better accuracy testing.
Steve
Good stuff Steve!
At this point I don't even consider brass bulged unless I can see the bulge before I pick it up. As long as they'll fit through the resizer without stripping off a ring of material, I consider them good to reload.
In my experience Blue Dot gets more accurate towards the top end, not really coming into its own until about 10.4~10.6 grains with a 180 grain bullet. Blue Dot has provided some of the most accurate loads I've ever worked up in 10mm.
I was getting pretty concerned with brass bulge...Underwood loads and Federal Trophy Bonded bulge like crazy...but I've yet to have one come apart. I think the heavy buffer is a reasonable safety precaution when shooting those loads. I haven't heard of any rupturing in the Banshee, but I have heard of them tearing in half and leaving part of the case in the chamber.
I've not seen any big discrepancy in accuracy between a cold and hot barrel, but every gun is different.
I second the BD accuracy, at least in a pistol format
Quote from: Muskrat on August 24 2020 07:22:31 PM MDT
Good stuff Steve!
At this point I don't even consider brass bulged unless I can see the bulge before I pick it up. As long as they'll fit through the resizer without stripping off a ring of material, I consider them good to reload.
In my experience Blue Dot gets more accurate towards the top end, not really coming into its own until about 10.4~10.6 grains with a 180 grain bullet. Blue Dot has provided some of the most accurate loads I've ever worked up in 10mm.
I was getting pretty concerned with brass bulge...Underwood loads and Federal Trophy Bonded bulge like crazy...but I've yet to have one come apart. I think the heavy buffer is a reasonable safety precaution when shooting those loads. I haven't heard of any rupturing in the Banshee, but I have heard of them tearing in half and leaving part of the case in the chamber.
I've not seen any big discrepancy in accuracy between a cold and hot barrel, but every gun is different.
I'm building a 1911 10mm using an original Colt Delta Elite slide fitted to an oversized Les Baer frame. Did all the filing and fitting myself. The gun is functional right now but still have more mechanical work to do and a lot of small cosmetic work. Then I'll get some reloads run through that and will concentrate on heavier BD loads as suggested.
I think I am going to transfer my Leupold scope over for some repeatable accuracy testing for now. And also do some heat tests to see how much influence heat my have on chamber pressure and bulging and also affecting accuracy. If I find it does walk, I'll tear it down and go through it and see what if anything can be done to improve this.
Hopefully we can get a good database of info built up here by comparing notes using several guns.
Steve
Got some more data fellas. I read earlier in this thread (possibly a different thread) about CMMG recommending Hornady brass to help with case bulge. So I have to know so I sectioned 6 different case today with the data collected below. See the included image also of 5 or those 6 cases for you own visual reference to go by.
In the attached pic the cases by brand from left to right are:
FC(Heavy), Starline, S&B, Hornady, SIG.
The reason for the FC heavy is that of the FC cases I have which are from the late 80's "FBI" load vintage. There is 2 distinct lots in this brass. One headstamp where the FC is smaller and embossed much deeper in the brass weighs a lot lighter. The more shallow and larger sized FC weight much more. I will get one of the FC light cases sectioned and compare to the heavy lot# and post back. Will also get pics of the CBC sectioned case.
Case Brands
SIG CBC S&B Speer Starline Hornady FC (light) FC(Heavy) LAX
75.1 76.6 72.3 68.0 71.6 69.9 71.6 78.3 75.6 = Avg wgt of 10 cases (gr)
0.0100 0.0100 0.0095 0.0090 0.0100 0.0100 = Neck wall thickness
0.0330 0.0330 0.0275 0.0270 0.0265 0.0320 = Wall Thickness at .300" above case head/bolt face
0.5520 0.5460 0.4810 0.5360 0.5100 0.6580 = Distance from case head to end of taper
0.1590 0.1770 0.1690 0.1650 0.1660 0.1920 = Thickness of case head webbing
Speer 200gr Gold Dots = .435" case bulge
Will post more data when I get it. But judging by these raw dimensions, the Hornady bass doesn't appear to be only stout sort of speaking. Granted these measurements don't prove anything about the metallurgy of the brass itself. But its still interesting none the less. My experience with Hornady brass with 2 different bottleneck rifles cartridges is that it is really hard and too brittle. Have gotten splits up the side of the body and necks on 30-06 and 243 brass on more than 1 occasion sometimes on the first reload (obviously 2nd firing after factory).
Hope this helps,
Steve
[attachment deleted by admin]
Just looking at pic. The Sig (Jaegerman ?) looks stoutest.
Thicker at base; tapered higher. Seems that structural analysis would bare out, but I'm not that guy.
Sent from my iPhone using Tapatalk
OK. Got the FC cases sectioned and pictures taken as well as more accurate weight data for you.
See picture IMG_4059.jpg for all 7 sectioned cases from left to right as they are displayed in the table below. I updated the FC Hvy and FC Lght case avg as I used a full 10 cases for these results rather than the above numbers which were NOT bases on a full 10 cases (only for the FC numbers!)
This table is sort from left to right starting with the thickest wall dimension at .300" above the case head. The reason for using .300" dimension is that is where the case bulge starts (i.e. .. lack of chamber support is right at this junction)
Case Brands
SIG CBC FC(Heavy) FC (light) S&B Starline Hornady
75.1 76.6 78.3 71.7 72.3 71.6 69.9 = Avg wgt of 10 cases (gr)
0.0100 0.0100 0.0100 0.0100 0.0095 0.0090 0.0100 = Neck wall thickness
0.0330 0.0330 0.0320 0.0280 0.0275 0.0270 0.0265 = Wall Thickness at .300" above case head/bolt face
0.5520 0.5460 0.6580 0.5360 0.4810 0.5360 0.5100 = Distance from case head to end of taper
0.1590 0.1770 0.1920 0.1620 0.1690 0.1650 0.1660 = Thickness of case head webbing
0.0445 0.0400 0.0360 0.0360 0.0350 0.0350 0.0340 = case wall thickness at base of taper
Also included is a picture called FC_case heads.jpg. This shows 4 cases each with the different head stamps. The 4 head stamps on the left to where the characters are not as deep and seem to be a little wider overall are the heavier weighing cases. The 4 case head stamps on the right to where the characters are embossed much deeper and are not as wide are the lighter weighing cases without exception. Just an FYI for everyone.
Steve
[attachment deleted by admin]
Quote from: sstewart on August 25 2020 08:57:01 PM MDT
The Sig (Jaegerman ?) looks stoutest
sstewart,
I researched a little and SIG claims their brass is made in house and not sub'd out. Just going by the internet, so I can't say with 100% certainty. But thier brass does measure up to be pretty darn stout.
To test out the quality of the brass metallurgy, I think I might take the SIG, FC Heavy and FC Light in batches of 5 cases and just load them over and over at 1 given load and see what happens for case life and where case failures might start showing up.
Steve
A friend recommended this super-cheesy brass-catcher for the Banshee, and it works GREAT.
https://www.amazon.com/gp/product/B07NW1H8WF/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
I don't have a lot of room left on my Picatinny rail and I didn't want to screw around with trying to find a better brass-catcher that might or might not mount up properly. For $9.00 this has proven to be a godsend for capturing brass. I don't think I'd run it in a combat shooting competition, but for range work it's just dandy. Seems to catch about 94% of the pieces, and the ones it doesn't catch just fall at your feet. Haven't had any jamming issues with it to date.
Lot easier than staking out a tarp...
I bought the "catcher" that mounts to the picatinny rail. Actually 3 of them. Got them with 2 recievers per bag and they have been perfect!
THIS is the best brass catcher around. Trust me I have 3 of them on my AR's and Banshee. The mesh doesn't melt and its adjustable fore and aft for scope mounting. Plus the name cracks me up because I call it the "gloryhole"....
https://www.amazon.com/gp/product/B07XH1VYD6/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Glad to see the debate on this thread is still going lol. I went out and shot a shit ton of 10mm this last weekend with my kids. PPU "which hasn't been mentioned in this thread" makes 10mm brass and it's not that great. Jageman brass seems to hold up better than most of the other's. I think Starline brass has kinda gone poo-poo with their metalurgy. It's just not very structurally sound unless i'm just getting unlucky shitty batches over and over....
Morning Fellas. New to the forum *wave* and wanted to chime in on this particular topic. Title says CMMG Banshee and brass bulges, verbatim for my search terms earlier tonight and how I came across this site. I'm comforted in knowing this brass getting plump around the base is not unique to my new pistol, nor the experience with customer service being tardy or non-existent from the company itself.
I'm new to the forum but not to firearms. New to 10mm but not 9. New to PCC's but not pin and weld shorty Ar's and so forth. Also, only just scratching the surface of reloading so if I say something ignorant, just do me like Skipper did Gilligan with the hat and we'll keep pushing. The world has enough thin skinned soy boys.
Got my MK10 around the 4th of July and the state in which I live immediately shut down the areas known for target practice until just this month for "fire danger" and "habitat recovery" which actually means there are a lot of Subaru foresters up the road at the trailhead with recent Cali transplants walking around with ski poles and imported politics in the summertime.
I was able to squeeze in one quick 2 mag range trip just to check function and had all that time in between to stare at this dirty grapefruit cup full of deformed brass. Thinking to myself in my limited knowledge "that don't look good". Some cheapy S+B 180 grain fmj that isn't visible really on up to Underwood 135 Nosler and 155 XTP that looks like a pear as someone here mentioned. The worst case I found in the 60 I let off was pushed out to .456" (XTP). I love this gun and all I could do really was read reviews and try to get a hold of our boys in the "Show Me" state. The best next step I concluded was to try other loads of course but I love Underwood and it has never been an issue with any other cartridge and dangit, I bought this thing because it's supposed to be "the one". I converted my G21 to 10mm with a lone wolf slide and got mags to match, created a system or "perfect pair" as they called it on Iraq V 8888.
So after all that thinking, I secured their 8 Oz. buffer and finally was able to go out last week with the same loads. Although they still swell up a bit, the worst deformation is down to .433" The thing runs flawlessly. I believe slowing it down did the trick. Holds open on Glock, ETS and SGM mags, 100% cycling even with the S+B. Recoil is soft like..with the heavy buffer there are almost stages to the recoil impulse. Almost feels slow like a very light load in a Benelli auto, but still capable of dumping rounds as fast as you pull it. The Banshee is sexy in bronze and quick with the 510 Holosun, wield-able I can imagine, half asleep in your drawers in the hallway chasing the bump in the night. Accuracy at 35 yards is 2" for me, good enough. By the end of the day I was hitting range leftovers at 50 yds. Small pumpkins, clay pigeons, Skoal containers. It's a fun weapon and after 600 rounds or so, it's next to my bed at night with a PL Pro Olight at 2 o'clock.
J.Fie welcome to the forum! 0.434" is what we see from the factory Glock barrels before the brass exhibits a distinct line form... "SMILE Line"
If the brass is smooth and rounded bulge it's possible to run those in a pass through sizing die like the bulge buster to restore the brass to a reusable state.
I personally use the LEE FCD die with it's carbide ring with the upper guts removed to pass through size all of my 10mm & 40 S&W brass.
0.456" is stretched out pretty far, so be careful and inspect them before and after any sizing and loading steps.
Quote from: Muskrat on February 20 2020 09:06:43 PM MST
Ya...makes sense. What you're doing is often cited as a way to turn a USPSA Major load into a USPSA Minor load without having to re-tool the loading press. So under most circumstances it should yield lower pressures and less bulging.
That said, 7 grains of Unique under a 180 grain bullet is a really mellow load. I'd be amazed if you were getting bulging of any consequence with that combo. If you are you might want to look at some other factors...COL maybe?
I've wondered about this too but I load everything the same for pistol/banshee per book specs. My press is never perfect from round to round however 1.250 to 1.260 will chamber in literally "everything" chambered for 10mm so that's where I set COL on everything I load. And 7gr of Unique isn't mellow by my chrono. Out of my XDM 5.25, 7.0 gr of Unique with 1.250-1.260 COL was pushing 180 gr slugs to 1,200+ fps....
I've loaded with AA#9 13.5 gr "same COL", Longshit 7.5 gr "same COL", and obviously Unique with same results as far as bulges go. Think I might buy the 8oz buffer and say to hell with it. I've done the power factor math and i'm knocking on the door 180gr x 1200 fps divided by 1,000 to technically use the 8 oz buffer according to the math that 22 plinkster said on youboob.