How tight should the gas lock be?

[matty86suk]

I don't think it's even possible on an in-spec gas cylinder and barrel mating to torque the whole cylinder enough to bind a piston - it is held in place by splines in the barrel and the casting is stronger (to prevent torsional warping) than you are ever going to be able to counter-act by torquing of the gas lock.

I didn't see your rifle and can't comment on it specifically, but if your piston was binding, it is FAR more likely that either your vent was plugged or you had some grit or a foreign object causing friction between the cylinder and piston.

I wouldn't recommend people file the gas lock to get alignment. The thickness dimension is somewhat important in setting plug depth. A far better solution is a standard shim job between the cylinder and the barrel shoulder. If it's a gas lock sight, good luck filing one - they are harder than most files.

I am telling you when i over tightened the GLFS the piston was binding, when i loosened it the piston moved freely, i never heard of this before but it happened, the GLFS from marstar was made from your harder than average steel, but i filed away about .015'', took some time, best option would be a surface grinding though, i had to do this to my current 2009 poly stock GL aswell, on this rifle the GL was either to tight or too loose, couple minutes with a file and calibre it fitted perfect, now by doing this the gas ports are aligned perfectly, now my piston sits 15 thou back but this doesn't change function at all, you could face the piston 15 thou and every thing would line up as normal....