This is something that has already taunted me before. Leveling scopes...here is whay I do, and when I'm done, it always looks out of whack, and I end up getting drift to the right as soon as I shart shooting past 500 yards. I made up a heavy steel plate with a vice welded to it and four bolts that act as adjustable legs. I lock the rifle in this. Using the Wheeler engineering "level, level, level!" I get the rifle level off the raceway and double check off the scope rail. I find some scope rails are off camber, and it varies along their length, but only by fractions of a degree. Then I'll mount the scope and get it level off the turret caps, double check and cross reference using the same level infrom the raceway to make sure everything is consistent. It is. Then get it snug in the rings. Next step is set up a plumb line 50 yards away to make sure. I use a 20lb weight on the end of the line and make sure there is no wind affecting it. Today, the scope, a Leupold mark 4 confirmed that the turrets tops (and flat area underneth) are pretty much perfct, though I did need to adjust it by a half tiny amount, maybe one degree. Once this is all in place I snug down the scope level, all the while maintaining and double checking that it stay in line with the plumb line and the rest of the levels. Once it is scung, double check again, adn everything is level. So this all sounds foolproof, but once I set up on the bipod, to get "level" it looks canted wayyy off, and always to the left, which with the last scope I set up like this, gave me right POI past 500. What the h@ll is going on?