Morning all,

Looking for some advice, 177 HW100k with A&M cylinder.

I haven't used it for a while, tried it yesterday and the POI at 25 yards had dropped about 3 mil dots.

Removed cylinder which vented any air left in it, put cylinder back on, refilled and appears to be back to normal.

Is it a cylinder issue or the reg in the gun sticking?

Cheers all