Quote Originally Posted by Shed tuner View Post
so reducing the valve stem diameter around the port will increase gas flow and raise fps, at the expense of gas consumption, yes.

but you are simply inputting more energy into a not particularly efficient system. The first mods I do to a 22xx are transfer port sealing (they normally leak) and an SSG, which noticably improves efficiency. A 19" barrel helps a lot too, but it's a bit long.

HTH - JB
And take coil off the hammer spring?