300 Norma Improved Bore Guide

This is a top of the line bore guide.  It is designed to work with actions that have a .750 bolt diameter.  The OD of the guide is .743.  The front has an O ring that prevents solvent from leaking back into the chamber and lug area.  The back insert goes over your rod and then fits snugly into the back of the bore guide.  This keeps your rod centered in the barrel and prevents it from rubbing on the rifling.