in the right direction. Although I didn't start out to tune my .22 QB78 (bulk fill carbine)for efficiency, I lightened the striker by boring the center out to within about .080" of the nose, and turning a delrin insert filler to bring the inside back to size. The "Old School Buttons", again a good idea, although I didn't use these as yet on my QB, they did work out well on my Disco using co2.
Most of things I've done on my QB was with the idea of bringing up velocity, lightened striker, opened up valve, teflon stem, larger trans port etc. But the interesting thing is, the speed did increase, shoots JSB's 700+ fps, the shot count for a fill is up to about 70. I'd think that another good tuning addition would a spring adjuster.