In all but one of my revolvers I shoot hardcast loads. I have a 7.5" Redhawk that shoots well with hardcast, but for some reason it absolutely turns into another animal with 300 grain XTPs. It literally is the one and only revolver that I shoot jacketed bullets in.
This is 5 rounds at 100 yards with the red dot equipped 7.5" Redhawk shooting the 300 grain XTPs. I have had rifles do worse.
Bear in mind that I shot a few 2.5" and 3" groups at 100 yards too, but still the thing absolutely stacks 300 grain XTPs, so that is all it is fed.
THE CHAIR IS AGAINST THE WALL.
The Tikka T3 in .308 Winchester is the Glock 19 of the rifle world.