Wow. Didn't think this was going to get so complicated.
I was checking zero before deer season and noticed I was having a number of flyers, which might be due to a bedding problem with the walnut mannlicher stock I just finished for my Ruger 77/357 that the Burris 4x sits on. The Ruger had been good for about 1 1/4" three-shot groups at a hundred yards with that scope, the factory plastic stock and factory ammo.
The receiver shape below the stock line is unconventional. The recoil lug is behind the rear of the magazine well. The front stock screw goes into a cantilevered extension of the receiver that has airspace between it and the barrel. I believe this is meant to allow the barrel to free-float completely (which it does with the plastic stock).
I've got the walnut stock free-floated as well, but I have to keep checking because of humidity and barometric changes we get. I'll shoot it some more with the forend cap left off because maybe that's got a little contact at the muzzle.
The scope adjustments weren't bringing the crosshairs back to the target center, so I figured I'd start from the beginning with the scope as well. Put RingTrue (tm) tape inside the rings, hand-tightened the base screws, leveled the crosshairs again, torqued the base screws to 30 in-lbs and the ring screws to 15 in-lbs. Thought I was good to go, but still couldn't adjust the reticle to the target center.
So I'm back to checking the bedding for the umpteenth time, confirm free-floating by moving paper slips between the barrel and the forend and maybe put a pillar in for the rear action screw.
Getting the scope back to factory zero before sighting-in seems reasonable. I can start out by putting the barreled action back in the factory stock and re-zeroing. If the scope adjusts normally and the rifle gets back to 1 1/4" groups then, I'll know that my wood stock is probably the problem.
If not, I'll send the scope to Burris to see if it's the problem.
