Quote from: bigboredad on March 29 2021 05:00:48 PM MDT
In 10mm the only small primer brass I've found is blazer

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I have both Federal and Blazer stamped SPP 10mm cases. Just scored some Federal SPM Match primers and am going to use them with that. Maybe try working up a powerful load with TCM and pulled 180 gr FN FMJ from American Reloading.

Quote from: DDRiller on September 04 2020 08:56:03 PM MDT
[quote
So the question i have then is why is H110 and similar powders acceptable for 357 mag, yet unsuitable for 10mm? Similar projectile weights, yes the charge/diameter ratio is different, but i think the roll crimp makes a difference.

You can't get enough H110 in a 10mm case to generate enough pressure to cycle the action.  A roll crimp won't help and the 10mm headspaces of the mouth.
[/quote]

I've actually run 220 gr PFN Xtreme with a compressed charge of H110 and CCI #350 in both a 16" PCC and my G29 w/ 4.6" barrel. (load worked up w/ a chrony based off 357 mag data, YMMV)

Recoil and blast felt like a full power Blue Dot load, but the velocity was about 50 fps slower. It fouled my PCC due to some unburnt powder residue. At the time I was also playing around with 40 super and seeing some of the same results, even though the case capacity was much greater (halfway between 357 and 41 mag actually), and I was using small rifle primers. Case head expansion and resizing effort on the H110 40 super brass was much improved over using N105/Longshot however.

Another option we now have available to try with improved burning of slow powders is using small rifle primers which I'm not sure anyone has explored yet. I have a couple thousand Fed and Blazer small primer 10mm brass in my stash now... One thing at time though, that's the scientific method.

Quote from: Muskrat on September 04 2020 03:39:37 PM MDT
I don't reload magnum handgun rounds, but I always believed that the purpose of the heavy roll crimp was to keep the bullets from moving under recoil, not to increase pressure or to accommodate slower powders. No?

I don't have enough expertise to make a definitive statement, but its hard for me to believe that you could hold the bullet tightly enough and consistently enough to slow down the burn and thus be able to use slower powders. Maybe it would work, but I've never seen any precedence to support it.

I guess the real question is what advantage is there to using slower powders? It's not like they quit production of the powders that are tried and proven in 10mm, including powders that exceed the original Norma load.

If you try it take meticulous measurements and notes! You'd be going WAY off the reservation on that one...blazing a new trail through uncharted territory most likely.

So the question i have then is why is H110 and similar powders acceptable for 357 mag, yet unsuitable for 10mm? Similar projectile weights, yes the charge/diameter ratio is different, but i think the roll crimp makes a difference.

Is there a die suitable to try this with 10mm?

Quote from: Muskrat on September 02 2020 09:06:39 AM MDT
Super-gluing bullets into the case doesn't seem real prudent to me. I don't have any idea how much it would increase pressure...neither does anyone else, so you'd be the test pilot on that one.

In addition, I think it would be extremely difficult to achieve consistent results, even under standard conditions. Now add variations in temperature, contaminants on the brass or bullet, new vs old glue etc., and who knows what the results would be.

10mm is a beautifully balanced round...but if you want .41 magnum ballistics, get a .41 magnum!

Quote from: oldman10mm on September 02 2020 08:34:20 AM MDT
What 'magnum' powders are you using that you're concerned about ?
Why do you want to 'mimic' a heavy roll crimp, why not JUST DO a heavy roll crimp ?

Well, since 10mm headspaces on the case mouth, a heavy roll crimp isn't going to work.

Yes, 10mm does headspace on the mouth but as evidenced by folks shooting 10mm with 40 SW, it can be done. Maybe you could cutdown 10mm mag brass slightly longer than 10mm auto to accommodate a roll crimp?

Just thinking out of the box here guys, I was hoping most of this has been discussed but maybe my Google-Fu is weak, because I couldn't find it.

Quote from: oldman10mm on September 02 2020 08:34:20 AM MDT
What 'magnum' powders are you using that you're concerned about ?
Why do you want to 'mimic' a heavy roll crimp, why not JUST DO a heavy roll crimp ?

I've thought of doing that, but not familiar much with that style of crimp (I don't load magnum rounds).

My thought was to try using some of the slightly slower mag pistol powders like H110/W296/LilGun/AA11FS/TCM, etc. which the powder manufacturers tell me aren't quite suitable for 10mm because there isn't enough bullet tension to get a suitable burn going.

As shadow mentioned, I've noticed pulling bullets from sealed rounds is definitely more difficult with a kinetic hammer so figured this would be a good discussion to address the issue.

Has anyone tried reloading 10mm with a heavy roll crimp? Does anyone use a bullet sealant and have noticed they need to reduce charges because of pressure?

Has anyone here ever read of using an adhesive such as superglue to mimic a heavy roll crimp like you see in the magnum pistol rounds like 357/41/44 mag? I know the military seals ammo with some sort of tar mixture for water proofing, but don't think that does much to neck tension based on my experience with a kinetic hammer pulling bullets.

I got to thinking maybe you could use a small amount while seating the bullet to allow the cartridge to build pressure with the slower powders such as H110/W296/AA11FS.

Quote from: aephilli822 on March 22 2020 12:58:48 PM MDT
So, what is wrong with MechTech, Hi-Point, or an AR?

This is an interesting discussion so BTTT.

The problem with the available 10mm carbine platforms is you cannot get enough slow burning powder in the 10mm Auto case to reach true magnum levels, even with a 16" barrel. I own a MechTech and a Banshee pistol and the slowest powder you can effectively use is AA#9. H110/W296 can work as well, but won't reach high enough pressures for a complete burn.

These pistol bullets have bad ballistic coefficients, so with a 100 yd shot, a 1500 fps 180 gr XTP will drop to about 1150 fps, a 42% drop in kinetic energy. That is still enough to maim and eventually kill thin skinned critters like people and varmints, but would not be ethical for medium sized game such as deer and bear in my opinion.

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.

So I picked up my Banshee 300 today.

Any updates on brass life reloading the Banshee Bulged cases? I don't see the need to push any speed records on my Banshee and want to work up a moderate target load with a little more recoil than standard S&B 180 gr FP.

I saw that 165 gr FMJ with 9.7gr Power Pistol reportedly is on the verge of bulging... has anyone use any of the slower magnum powders like AA#9? I have a large variety of powders to choose from and want a economical target round to make a few cases of.

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.

We'll see. I have a large stock of AA#9/7, N105, Longshot and Blue Dot if it doesn't perform.

If only some of my ranges were open so I could try it. Its either that or a 2 hour drive into the boonies on BLM land which seems pretty sketchy in these times.

I'd like to know too. Based on the burn rates and published data from AA I bought the last 24# that Powder Valley had for use in 10mm and 300 BLK. Maybe some wheel guns one day too.

Based on the 357 Mag data this stuff should blow AA#9 away for 200-220 gr pills and offer a lot of crossover opportunities in 300 BLK as well. I have a ton of components earmarked for suppressed 300 BLK use so will NOT be running short on powder this election cycle/wuflu panic.

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

Why stop at 15 rd mags? The SGM Tactical 30 rd mags work flawlessly in mine.

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.