My late 2 cents.....I've never crimped any of my cartridges for my singleshots and never had any problem with accuracy/velocity once the right combination of "things" is arrived at( right powder,primer, bullet etc). My two NEF's(45/70 and 22 Hornet), Ruger #1(6mm Rem) and Savage 24V (22 Hornet) all shoot minute of angle or less. I was always taught to crimp only when necessary(magazine rifles). But everyone experiments, that's part of the great pleasure in shooting.