offsetting scope bases

[rr1220]

i was wondering if offsetting the scope base instead of shimming the rings would work; example-weaver #15 base for front weaver #16 for rear,this would give me .010 offset as opposed to shimming and give me about 8 moa in elevation
any experience or thoughts on this

[yankee]

In either case you may end up with the front and rear base not being level with each other. Then when you tighten the scope in the rings either the front or rear of each ring will make a mark or dent on the scope body. To eliminate this problem the rings need to be lapped so the saddles of the rings are level and you do not dent or mark the scope. Once you lap the rings they pretty much need to stay with the rifle, base combination. The other way is to get rings with a rotating insert. Years ago Jewel made some but I haven't seen those in 15 years. So now the answer is to use the Burris Signature rings with the plastic bushings. These seem to work great but remember to clean the oil off the rings and bushings. This is why people get the tapered bases. They match the receiver on the bottom are tapered then are square and level on the top to properly align the rings. BUT FIRST mount the scope with the standard bases and rings, sight in the rifle and see if you need the extra elevation.
The reason this is being done is.
1. The scope doesn't have enough elevation to sight in on the further targets
2. You are trying to use the center of the turret adjustment - "this makes most scopes work best if you are changing elevation and windage as we do in silhouette"
The bottom line: you are trying to put this thing together with everything square, level with 100% contact. If not something will be in a bind. If it's the scope you dent it and it also may not work properly. If it is the action the rifle won't shoot like it should.

[jrebelo]

As mentioned, offsetting bases will cause the less of the inner surface of the rings to contact the scope tube. The less the ring's contact area, the greater the theoretical risk of denting/bending the tube or possibly damaging/hampering internal adjustments.

Shimming inside the ring isn't much more ideal, but I've done it with scopes I am not too attached to. For any scope I care about, the only thing I will use is Burris Signature Zee rings, which have plastic inserts that act as bushings between the scope tube and the scope rings. These inserts come concentrically equal, but you can purchase (for about $20) a set of offset inserts, allowing you to 'shim' the scope +/-5/10/20 MOA *safely*. The reason is that the inserts move around within the rings so that you could do +20 on the rear and -20 on the front (for a total of +40 MOA elevation) and the scope will still be perfectly centred within the inserts because of how they float inside the ring.

You can also adjust the rings left/right to get your scope zeroed for windage without having to use any internal adjustment while still getting the elevation gains out of it.