I'm going to have to disagree with you there mil-surp60, that ain't the way the Russians did it. The correct way to zero a mismatched or put together PU sniper is to first mechanically center the reticle in the tube then make adjustments using the two set screws in the base for elevation and by filing or shimming the ''feet'' on the mount until it shoots center horizontally. Zeroing by using the windage and elevation adjustment on the scope alone will result in an off center aiming post. If there's one thing I can't stand it's a canted or off center reticle.
Complete step by step instructions on zeroing a PU can be found at www. mosinnagant.net. Check it out, good info.