I’ve been looking for an RDB for years when two weeks ago my local gun store happened to have two in stock! I grabbed the tan one - serial number Z0U2x. In anticipation of finally taking it to the range I stripped it down, oiled it up, and stole my Primary Arms 5x ACSS scope from a different gun and boresighted it. This morning I dragged everything to the range, zeroed the scope, and was getting 1 5/8” groups at 25 yards! This was with a Caldwell shooting rest. Taking it out to 100 yards the group opened up to 6.5 inches! Based on shooting my other rifles with this same rest, my contribution to that group should have been no more than 1/4 inch. Even my self-built junker AR can get 2.5 MOA. The gas setting was +1 above how it came from the factory. The bolt wasn’t coming all the way back with the factory setting. It would eject and lock back, but not the last quarter inch or so which means I couldn’t use the bolt release. I had to use the charging handle to pull it back the last bit (which was very stiff.) Has anyone else had such a bad grouping? Before anyone asks, all rail screws were tight (the screw between T8 and T6 managed to turn about 1/8th turn, but it didn’t help the groups.) The scope bolts were tight. All takedown pins were in and nothing else on the rifle seemed loose. Anything else I should check for? Thanks in advance for any help! Neil Edit - this was with Armscor 62 grain FMJ ammo.