Thomis,
Ah, OK, I checked out the lapping kits you were talking about. Uhhh, I don't know. Seems like a lot of fussing around, unless you know you really need this extra step. The ad copy at the Wheeler Engineering product made it sound like you only need this lapping for the heaviest recoiling rifles. To keep rings from slipping on the scope barrel. And even then, it won't keep the ring-bases or the rail from slipping on its/their attachment points on the receiver. If your scope mount is a Picatinny or Weaver rail, some folks bed the rail, which is some work but basically free and does provide a stable surface for the rail. If you're just shooting large animals at < 200 yds, and the rifle is otherwise decent, I advise to spend your money else-wise.
I honestly don't think a properly manufactured and torqued ring/clamp at the scope tube will slip. Spend some money on a torque wrench or torque screwdriver, maybe.
Also, for my rifles that can have a Pic or Weaver rail, I put one on and use it. They now make integral two-ring mounts for bolt guns, like this:
If the two rings are not perfectly lined up at the factory, send the unit back for replacement. Either that or your scope tube is already bent.
I have a couple of these GG&G Accucam units. I can swap either of two scopes on a rifle, and the previous zero does not shift. Well, I can't tell, shooting normal groups. I'd have to shoot super-careful groups and average several to tell if anything has shifted or not re-seated exactly. I think any re-attachment shift is well within the unavoidable thermal expansion/contraction shifting, wear/tear/bumping shifting of a permanently mounted scope.
I think it will be possible to use the same scope on two different rifles. Just dial in a pre-zeroed offset of elevation and windage for each rifle. I haven't tried it yet, for lack of range time, but I believe these modern quick-detach integral bases will be good enough to permit it.
