The autos used in bulls eye competition are not off the shelf guns.
And neither are the revolvers!
Every tweak or modification allowed within the rules is used. Sights, grips, trigger & action jobs, etc. If its allowed in the rules, it is being done, by most, if not all. Other than matches where no modifications at all are the rules, the next time someone wins a major match with a completely bone stock off the shelf gun will be the first time in a very long time.
Consider for a moment the Contender. It has the fixed barrel & sight relationship of the revolver, and the solid barrel & chamber of the auto pistol. And generally, will out shoot both in terms of accuracy (group size).