For me, the ideal way to order any reamer when the length of bullet to be used is in question, is to order the reamer with minimal freebore length, say .020" in order to gaurantee good obturation, and then a throating reamer that will allow for the cutting of an optimal freebore that will put the shank end of the bullet right in the middle of the case neck or where ever I want it to suit my needs. Throating reamer only costs and extra couple of dollars and can be used for any future cartidges in the same bore dia. class..............Don