If your short barrel PCC shows case bulge on that version of AAC ammo, then it confirms that the AAC cases are either soft or thinner than some other brands. But if you don’t see any case bulges, it doesn’t confirm or not if the XTP “hot” load has a minor issue in PCCs.
I believe AAC uses the same cases in all their 9mm ammo.
I don’t know if they use the same amount of powder or type of powder (fast burning, slow burning, etc).
When you shoot some of your FMJ, post case result and your buffer weight. Thanks !
Went to the range today. I took a Foxtrot Mike FM-9 blowback PCC and a CMMG Banshee radial delayed 9mm PCC. Shot 10 rounds of AAC 124 grain FMJ through each, collecting the brass in a catcher to keep it separate. I can’t measure a difference in diameter from the new bullets to the spent cases. The Banshee is maybe .0005” larger, my digital caliper measures in .0005” increments and it’s flickering back and forth on those casings.
Both guns are equipped with HBPDW braces, the FM-9 uses the 9mm specific version with a 7.8oz buffer weight and FMP’s 14 oz bolt. 21.8 oz combined.
The Banshee runs the 5.56 version of the brace with a 3.1oz buffer weight and CMMG’s 11.7oz bolt. 14.8oz combined.
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I just had an AAC 124gr FMJ case rupture, yesterday, in my Dagger. Not sure if it’s related.
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Wow, your split case is much worse than the bulges I noticed with the 124gr XTP (8/24/24 post).
Yeah. I’ve never had it happen, before. I was shocked. Not sure if it’s a problem with the bullet or the gun, but I’ve put many hundreds of rounds through the gun without a problem.
