Cmmg Banshee and brass bulges

[sstewart]

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.


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[SteveinNC]

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 



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[SteveinNC]

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

[Muskrat]

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...

[terdog]

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!

[phaloxx]

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....

[J.Fie]

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.

[The_Shadow]

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.

[phaloxx]

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.