I had a heck of a time with my Trail finding a pellet that was accurate but half the problem was I was using a rest and putting the butt in the rifle rest and like you I could not get a consistant group.I Found the solution and it was to take the butt section off the rifle rest and just support the forearm on the V of the rest.It shoots really tight groups with the Superdomes now.I also taped pipe insulation on the V of the rest and it made it a little less jumpy when you shoot it.
Nice numbers, very even. Jeff