I've seen the question come up with respect to zeroing a S&B scope that has the MTC and locking turrets. The procedure for these scopes is different from that listed in the PMII owners manual (unless something has changed recently). We run a few S&B scopes and until now, didn't need to make adjustments from the factory zero. Once we started zeroing them for various caliber weapons required for our testing, we ran into some issues. The amount we dialed to zero did not hold. I talked to Jerry at the service center and we were leaving out a crucial step required for these scopes. It turns out that S&B added an additional o-ring in the turret and if you do not maintain downward pressure on the turret during the adjustment, the o-ring will hold the turret up slightly. The turret being slightly raised, will not engage or disengage as required for the zeroing process. Since using the procedure below, we have not had any problems.
1. Lock turret by pushing down on locking collar
2. Loosen the two set screws one-half turn
3. Unlock turret by pulling collar up
4. Without locking it, push down on the turret to maintain downward pressure while turning to zero
5. Continue to push down on turret while tightening set screws
1. Lock turret by pushing down on locking collar
2. Loosen the two set screws one-half turn
3. Unlock turret by pulling collar up
4. Without locking it, push down on the turret to maintain downward pressure while turning to zero
5. Continue to push down on turret while tightening set screws
