IMO single shot tray is single shot tray , unless you are feeding the pellet sideways or backwards through it .
Mine was initially exhibiting a small amount of shift from session to session, something like 1/2” at 30 yards. Usually this symptom can be traced to some source of play or movement between parts. In this case, none of the usual suspects seemed to have any play 1. Fit between the barrel and shroud – the plastic spacer was a firm fit to the barrel and the O-ring on its OD produced a suitable interference fit with the shroud.2. Fit between the shroud and barrel band – the screw on each side put a little squeeze on the plastic balls to support the shroud within the barrel band.3. Fit between the barrel band and stock – no play detected here either However I turned my eye to the shroud’s rear support bushing…the one next to the receiver. It had a single screw that simply pins the shroud to it. The side opposite the screw has some freedom to move so I drilled it for a second countersunk screw. It was a long shot but somehow that seemed to do the trick. Been using it for several weeks now and the POI shift has not returned.
Haven’t had time to read all replies so maybe this was mentioned. I had two avengers and a Donny adapter and an aftermarket extra barrel band cured any poi. However I have also read that a barrel band could possibly be the cause. When you fill the air cylinder (esp over 4k) that air tube will slightly expand. If the band is touching that and the shroud it will certainly push the shroud/barrel slightly causing shifting poi. Now I never filled mine past about 3600-3800 psi. Maybe try filling it slightly less and see what happens.