Well, I'd suggest a good cleaning and lubrication, then try some new ammo (new as in newly purchased, fresh). If that doesn't fix the problem, then I'd try buying and shooting a box of CCI Velocitors. This is a high-powered (for a .22) load, with a heavy bullet at higher-that-normal speeds. When I shoot this in a semi-auto (rifle OR pistol), I can feel the extra "thump" the bolt/slide makes due to the powerful ammo. If your gun needs a bit more oomph, this ammo will give it to ya.