If your brass does not hang onto a bullet well enough, it can make a difference on 50-yard precision targets. Assuming all the brass hangs on well, it gets harder to tell a difference. A lot of guys sort by headstamp for rifle shooting. A good target rifle for position shooting can shoot half moa, while a good pistol for bullseye shooting can shoot 4 moa (2 inches at 50-yards and a really exceptional one can do half that until it shoots loose). So, with four to eight times lower accuracy expectations, a lot of the ammunition loading steps that can improve groups with a target rifle make invisible differences in pistol and revolver ammunition and can generally be ignored.
The thing to keep in mind is that each source of error adds a certain amount of randomizing to the total area of a group, not to the diameter of the group. So if eliminating a particular source of error takes away a tenth of a moa² of the area from the size of a group, that takes a half moa group down to a bughole, but a four moa group is only reduced to a 3.97 moa group by removing that same area. So it's not a reliably detectable improvement in common handgun ammunition without firing and averaging a large number of groups.
The thing to keep in mind is that each source of error adds a certain amount of randomizing to the total area of a group, not to the diameter of the group. So if eliminating a particular source of error takes away a tenth of a moa² of the area from the size of a group, that takes a half moa group down to a bughole, but a four moa group is only reduced to a 3.97 moa group by removing that same area. So it's not a reliably detectable improvement in common handgun ammunition without firing and averaging a large number of groups.
