Hornady bullet comparator set - Hornady Lock-N-Load Bullet Comparator Basic Set

If you need to know the exact dimension of you rounds, this is the tool. If you're dealing with a bullet/leede tolerance in the "thousands" you need to know your exact bullet size. A must have for reloading and in many rifles.
Pros: Precise measurement
Cons: none

This review was written in the old system and had content requirements that are different than reviews written today.