Grump
Member
Help me understand this...
The pistol was shooting low, so you suspect it was not going fully into battery? With that tilt-barrel locking system, that leaves the back of the barrel low, shouldn't that make the rounds go high?
Unless I missed something here, these are all .45 ACP USPs. Are they not fully-supported in the case wall all the way back to the forward edge of the extractor groove, like the .40 caliber USPs I've seen?
If not, never mind. If so, holy smoke, you should have a case web of something like 2 mm or more of solid brass between your powder chamber and the extractor groove. 1903 Springfield rifles in .30-06 chamber the round only up to that part of the extractor groove, and their brass holds just fine.
I vote for very bad ammo causing this.
I also vote for the USP's plastic maybe not being quite flexible enough for foreseeable ammo-caused disasters. Of course, the wood grips on 1911 Gov't Models are also under-engineered for that as well. I seem to remember those who used .38 Super loaded to the older IPSC Major PF of 175 recommending steel-lined grips before the fully-supported ramped barrels became standard equipment for that game/caliber.
Note that none of these involves a barrel or chamber actually letting go. It's the brass case, in these instances one from a moderate-pressure cartridge.
The pistol was shooting low, so you suspect it was not going fully into battery? With that tilt-barrel locking system, that leaves the back of the barrel low, shouldn't that make the rounds go high?
Unless I missed something here, these are all .45 ACP USPs. Are they not fully-supported in the case wall all the way back to the forward edge of the extractor groove, like the .40 caliber USPs I've seen?
If not, never mind. If so, holy smoke, you should have a case web of something like 2 mm or more of solid brass between your powder chamber and the extractor groove. 1903 Springfield rifles in .30-06 chamber the round only up to that part of the extractor groove, and their brass holds just fine.
I vote for very bad ammo causing this.
I also vote for the USP's plastic maybe not being quite flexible enough for foreseeable ammo-caused disasters. Of course, the wood grips on 1911 Gov't Models are also under-engineered for that as well. I seem to remember those who used .38 Super loaded to the older IPSC Major PF of 175 recommending steel-lined grips before the fully-supported ramped barrels became standard equipment for that game/caliber.
Note that none of these involves a barrel or chamber actually letting go. It's the brass case, in these instances one from a moderate-pressure cartridge.