In that case you can go to Brownells (for one) and buy steel shim stock and cut a shim to match the scope base. The idea is to blue shim and have no unsightly gaps or lines between the base and the receiver. Brownells also sells a scope shim kit punched out of steel and blued. At least try to use one decent looking shim rather than a stack of pop can bits.
scope shim kitsteel shim stock assortment
