Shooting Rams at 500 meters using a 44 magnum required over 50 MOA taper added on my one-piece scope base. Here is link to an article on how I tapered the one-piece scope base by hand for my Contender. I repeated this hand sanding process successfully on a 221 Fireball Barrel one-piece scope mount. I added 13 MOA to the elevation and centered windage using this hand sanding technique.

Tapering an One Piece Scope Base