It's all in the shooter.But I think different sight designs have alot to do with "long range" accuracy.
Most handgun front sight blades are wide enough to cover a 2" area of a target at 25yrds...kinda makes it hard to pin-point every shot without lots and lots of practice with the same gun,form,ammo(you'll need a nit-picky hand loader here) and conditions.
But,as everyone else has stated....It's the shooter that pulls the trigger.
I was at the range shooting my Star BM (old surplus 9mm).I was getting decent 4" groups at about 15yds.Then my buddy hands me his NEW S&W 9mm.It has a longer barrel,isn't worn out and is of a newer design.I should get great groups with this ,I thought.NOPE...all over the map with the first half of the magazine.By the time I when through 2 magazines I was hitting the target with slightly better groups then my BM.
It goes to show...not all 9mm's react the same and it's up to the shooter to staighten it out!