The gun: rock river upper, 20 inch barrel, 1x9 twist, the lower is a double star with a jp trigger. Brand new leupold rifleman 4-12x40 scope Burris pepr mount.

We can not get tight three shot groups with the gun. It's averaging about 3 or 4 inch groups. We have tried black hills 62 grain, 55 grain pmc bronze fmj, 55 grain federal fmj, and 55 grain Winchesters that were soft points I think. All shots were off a lead sled with little to no wind. The barrel had plenty of time to cool in between shots and all rings and mounts are tight. The gun was bought used so we do not know round count. Any ideas?
Team M.I.A.