I have a 700 that might have its base hole alignment slightly out of wack, not much but enough to notice on a collimator. It might be the mounts or the screw holes. I mounted DNZ 2 piece mounts(which suck) and got that result. I ordered talley lightweights to see if there is a difference or not. Scope is a Zeiss DL which has given zero issues in 3 years I have owned it .
Will 6/48 to 8/40 improve the alignment ?
I have been through this process several times, not just due to misaligned holes, but wanting the extra ‘beef’ of a 8-40 thread.
The only way to do it correctly is on a mill with the centreline of the action found and to mill the new holes precisely. This is often all you need to clean up the existing hole, if not, then the old holes will need filling, either by a blank threaded plug, or EDM.
I have a Win Model 70 EW with a misaligned hole on the front bridge, you cannot see the misalignment until you place a straight edge over all 4 holes and it is enough to feel the screw drag as you tighten it.
Looks like my next job will be to open those holes up to 8-40 to get things aligned correctly. Well, when I get time...too busy hunting with it.
