Another way around that von Zelda is that after Locking on to your target, switch tubes. I have not tried that in Stock lately though, only in FotRSU. I'm reasonably certain that's a "game" thing. I don't use the Lock button anyway. I just point the scope at the target and hit the PK, then shoot. Where you aim, is where you'll hit - sometimes...

- If you want to ~really~ laugh, watch me do manual-targeting...