[mikld]

Calipers aren't necessary for reloading any straight sided handgun ammo. All bullets designed for revolvers should have a crimp groove or cannalure, and bullet seated to the groove/cannalure, regardless of OAL (as long as the round fits the cylinder, not too long). I reloaded for 18 months or so with only a Lee Loader, made a thousand rounds or so, crimped all the bullets in the crimp groove and shot them all without knowing the exact OAL. Continued to reload revolver rounds with my single stage press/standard dies for a few years without measuring OAL; 38/357, .44 Spec./Magnum. And today, 30 or so years later, I still don't know exactly the OAL of any of my revolver ammo.

A micrometer is a must for reloading lead bullets in any gun as calipers aren't accurate enough for bullet OD (not starting a debate on caliper accuracy, I've used them as a machinist/mechanic for nearly 40 years and even down to .0005". But rarely do new reloaders have the "feel" or experience with a caliper to be accurate to .001". my .02...).