Find the mechanical flaw shown in this photograph:
Bonus points for correctly guessing the result of the flaw.
Find the mechanical flaw shown in this photograph:
Bonus points for correctly guessing the result of the flaw.
Crap - does the rim of that .22 cartridge extend beyond edge of the bolt-face? And if so, how was the machine-gun demonstration?
[AK]Abaddon
Actually, no, the bolt-face is in spec.
The problem is that there is an inordinant amount of slop between the extractor and the rim of the shell casing. So much so that it's not gripping the rim at all. What's worse, is that the extractor is spring loaded, so is exerting a force against the side of the casing. That force is in the wrong direction and effectively the casing pivots downwards (in the photo). The ejection port of the pistol is upwards (in the photo), so the casing is pivoting into the wrong direction. In application, what happens is the casing ends up "ejecting" in the wrong direction and ends up stuck inside the reciever - causing a jam. Which explains why about once ever 20 rounds I get this exact type of jam. I've been battling the occassional jam like this for many years, and never really knew why.
Apparently there's a cottage industry that makes shorter extractors for this very reason. I have one on order now, as a matter of fact.