Put a clamp level on the barrel BEFORE you take that other level off the rail. Wheeler makes a good set for that. You assume that the rifle is locked in place... It's not. It doesn't take much to knock the rifle out of alignment. Take off the turret cap. Don't assume the cap is parallel to the bottom of the turret housing. I found out the hard way with that one. Ditch the vortex bubble. I've had them on a few scopes and they always shifted at some point (usually during transportation). Get the level that attaches to your pic rail and folds in when you're not using it.
Put a clamp level on the barrel BEFORE you take that other level off the rail. Wheeler makes a good set for that. You assume that the rifle is locked in place... It's not. It doesn't take much to knock the rifle out of alignment. Take off the turret cap. Don't assume the cap is parallel to the bottom of the turret housing. I found out the hard way with that one. Ditch the vortex bubble. I've had them on a few scopes and they always shifted at some point (usually during transportation). Get the level that attaches to your pic rail and folds in when you're not using it.