Mini boom

[vluc]

I have extra G34 barrels and have run them from time to time in both of my pistols with no issues. But then I've had occasions (mostly) where I have had no issues with the original barrels. 

Remember, these 8 are spread between 2 similarly set gen4 glock 34's run weekly from March through October. Usually shoot a match twice, switching guns. Chances of both barrels having issues is unlikely, I've not had it happen during any live fire plinking, just matches, so it's either me or the brass. 8 out of many thousands shot leads me in that direction. 

I do appreciate the perspective of other shooters. I'll make a number of adjustments, run with a different lot of brass and see what happens. 

[Absocold]

Ah, missed te part that it was two different guns, sorry.

 

Pull a couple bullets and check for over-crimping. Chrono your load and make sure you didn't get a hot batch of powder. If everything else checks out, it's the brass.

[RJH]

Is that brass stepped? in your pics i can never see the headstamp, and there are none on the interior of the case.  If they are,that could cause slightly high pressures and cause the brass to blow out.  Either way i think it a brass issue nit a gun issue and i don't even like glocks haha.  I have seen brass fired out of an open gun with quite a bit of bulge on the bottom of the case and i would think that they would have to be weakened.  I figure one of those two things are the issues.  I would be a little more vigilant in sorting brass and not worry about it too much