I recently purchased a pre-owned SN-3 5-25x58. Previous owner sent all documents/paperwork that came new with the scope. The only thing I'm not seeing is how to zero the windage turret. I'm guessing you loosen the machine screw in the middle of the turret, set to zero, then re-tighten, but don't want to screw up or do something I shouldn't. For clarity, I have the US#3 M40 1/10 MIL turret.