I am an old benchrest guy that has tried every tick in the book at on time or another. The short version of my opinion is: I only crimp for pistols, 22 Hornet, and cartridges that have significant recoil (375 and up). Hornets have very thin brass and the big boys tend to seat bullets deeper in the case for cartridges that are in the magazine during firing. C type presses are good for fast loading, O and H presses are better for accuracy. Concentricity is a rabbit hole that is best avoided, but proper presses and dies take care of any real problems so no worries. Tight target chambers behave differently than those on "normal" rifles. Most guys shooting ladder tests because they read all about them on the internet are wasting their time and powder. Guys that wear their hair in man buns are goofy.