I just wanted to share this info. I have a six months old .22 Discovery and it had three problems: a POI shift after pump-ups; a smaller POI shift as the pressure changed; and it did not like RWS Superpoint pellets. They would hit about 4-5 inches below and a couple inches to the right of round nose pellets like RWS Superdomes and Benjamin domed hollowpoints. Because it was on my list of things to do, and I am not a good mechanical type, I sent the .22 Disco to Mike at TKO for a tuning. One thing that he found was that the breech screws were loose. That could cause all three problems. The gun is great now. The POI shifts are gone and the RWS Superdomes, Superpoints and Benjamin domed hollowpoints all hit the same POI when I reshot the gun at 20 yards. It also chrony'd at 815fps using 15.9g JSBs for 23fpe. So, for folks that may be experiencing some of the POI problems and maybe some really out of wack pellet problems, one easy check would be to see that the breech screws are tight. My next step is to sight t in a 30 and then maybe 40 yards and see how things go. I am also very please with the TKO22 tuning. One theory about the Superpoints being so far out of wack was with a loose breech, the pellets were not going in far enough to pick-up the rifling, and thus had a slight yaw/wobble when fired. All is fine now.
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