ORIGINAL: TradTech
More than likely, your perfect bullet hole you had prior to group/walkback tuning will be gone.
Nope, not unless you have clearance problems. If you are shooting bullet holes thru paper, and then walk back or whatever, a properly setup combow, the holes shouldn't change at all.
I have seen a bunch of people (even bass protuners) say this and you can clearly see on thier cock vane that they have clearance issues.