I can spin, draw and fire with my walther cp88 and get a 1 inch group at 200 yards.
Daystate mk3 RT with Bushnell Trophy 6-18x40
Recommended deals with: mrfixit, Steve83, Merlyn, johnyjohnjonno
At the muzzle, less than 10 f.p.s. At the target, often double that outdoors. I used regulated and non-regulated rifles, springers and gas-rams. Incidently, the two occasions I clamped the precharged rifles' actions to a rig, the groups actually got worse.
As so often happens, there are more questions than answers, mate.