Rifle was cycling properly and then stopped after 250 rounds

[kolob]

We've had this happen a few times.  The first thing to check is your gas block.  Once in a while the gas block comes loose and moves forward.  If it moves forward, it will not let the gas go where it should and it won't cycle.

Just undo the allen head screw.
Move the gas block into place.
Re-tighten the allen head screw.

There's always a little gas which leaks around the gas block. This gas actually locks up the allen head screw so no Loctite is needed.   This usually happens if that screw was not tight enough to start with.  Once it's tightened up right, it will never come loose on its own.

[aziator]

Had this happen on my friends gun.  Was shooting it one day and the gas block loosened up.  Pulled out my allen wrench and tightened it up and haven't had any issues since.

Alex, thanks for posting these quick fixes for those that may not have seen them yet.