Jammin' Glock???
My GOD man! Delete this before gocart and tetchaje1 see it! They
won't be able to sleep!
(Sorry...Couldn't resist.)
HiFidelity, I'm not too well boned up on Glocks, but when it does it again,
look closely at the bullet nose to see if it's caught on the leading edge of
the barrel throat. If not...and this is a shot in the dark...check the
slidestop to see if it's slightly engaged in the slide's notch and simply
locking the slide back as though the gun were empty. If the slide stops
without touching the round, this is probably it.
If the slide has pushed the round forward, it's my guess that it's catching on the bottom of the throat. If the round is in the chamber and it stops, it may be stem bind. Look for a crescent-shaped mark on the side of the case just below the case mouth. It may be relatd to the cartridge overall length. Some pistols are persnickety on that point.
A rough breech face can cause this, and can also contribute to stem bind
with certain cartridge lengths...as can an extractor related problem.
Hard to say without seeing it...A picture would help...There's some pretty
sharp Glocksters here. One of'em will nail it.
Luck to ya!
Tuner