How much inconsistancy can lapping remov? I have a rifle that the bases are a good .10" off.
I've heard of bedding the bases concentrically in epoxy instead of lapping when they are really off.

Perry

That is a bunch of OFF. .10 is almost 1/8",are you sure?

JK is right of course; lapping ain't going to correct that error. Lapping is only to true up the rings a few thousandths.
You have to redrill the receiver, or you can elongate the holes in the offending base and move it into alignment; then epoxy it or solder it in place. Move one base to match the other; best the rear one.
Or use a one piece Redfield/Leupold base and hope it is straight enough to zero your scope.

How about buying blank bases and have Jim Kobe drill them to match your receiver?

Are the bases off side to side, or is height the issue?

If side to side, get blank bases and drill them to suit.

If height is the issue, either shim the low one or machine them to to suit. This is easy on a round receiver (like a Remington 700), harder on some others.

Howdy -- what action, what bases? which directions are they off? is the ACTION off, s to speak - like a badly ground front ring on a mauser, or are the off set, you a roll axis?

Problem in the bases? fit the bases to the receiver square to the world...I do that with most of my rifles that have QD rings..I center the cross hairs to the scopes focal plane usually by turning the adjustments from start to finish, then going half way back, that centers them..then cut the bases to fit that, usually finish by hand..I want the gun to zero in the center of the adjustments...When a gun zeros at the end of the adjustments your not in the center of the focal plane, and the scope tends to fail in several ways such as it won't hold its zero well as a rule and the brightness is less as is the field of view..

Actual lapping of scope rings is in many cases over done and the rings can no long snug up the scope and the gun won't hold its zero..A piece of 400 grt. paper wet, will take of the edge ever so lightly on the rings edges to prevent scope marking, and that will work..I avoid scope lapping like a plague.

If you have to lap the rings, something is wrong. The bases have to be level and aligned with the bore. After that it's all downhill.


dave

Over-lapping is a whole different thing than light lapping to allow scope mounting w/o marking or scratching the tube. It's never to actually "align" the scope mounts/rings, scope... or shouldn't be.

If you "avoid" lapping, it's because you or some gorilla over-did it. Pretty simple

Zeke

Thank you gents for the guidance.
It sounds like the receiver needs a gunsmith. The holes are way off.

Perry

quote:

It sounds like the receiver needs a gunsmith. The holes are way off.

If the rifle is new, ask for a refund or replacement.

Dave

Very true Lapping is to clean the edges only and that can be done with our finger and some 400 grt. paper IMO, but lapping done properly is a good thing..Only thing is its a much abuse process..

I usually surface grind the action receiver or have it done for $50. then hand fit the bases and that way all is square to the world..It works especailly on QD mounting systems as to return to zero..clean the rings edges with 400 grit..and blue..Its worth the extra on a hunting rifle to help hold its zero is another plus. It also keeps the cross hairs zero in the center of the scopes focal plane or the adjustments location.