Home Forums Hunting & Shooting Predators and Varmints what am i doing wrong????

If the forward screw on the front base is too long it can either bottom out in a mounting hole (in a few cases the hole is a blind hole not drilled through the action) or it can bottom against the barrel shank threads. When this happens the forward screw will be tight but the base is held securely by only the rear screw. Further, if the forward screw has tightened against the barrel shank threads, placing strain on the barrel and receiver junction, this causes a shift in point of aim. Changing to another base set or screws can eliminate the problem randomly when the screws are slightly shorter or the base a bit thicker.

Mounting a scope is a lot more complicated than we are led to believe. Below is a base screw that would tighten against the barrel threads before tightening against the base. The base itself would interfere with the recoil lug.



In this photo the screw has been shortened only a few thousandths and is now clearing the barrel allowing it to secure the base. The total length of this screw is .290". Shortening the base provides clearance with the recoil lug. This is something that would be missed under normal circumstances, but becomes obvious if the bases are fitted with the barrel removed. Also any distortion in the bases or rings, or over tightened screws can play havoc on a scope.