Mikecr was trying to link a thread. It did not work for me. But this issue has come up many times. If you are using the brass, SUPPLIED, by them, it is not fireformed to your chamber.And as so I found that my gauge brass where off .005-.007 .If you send in your fired brass for gauge then no. You need a shoulder type gauge and comparator to find this. For this reason I USE THE Sinclair tool.You use your own fired brass. Also I bought a tap to make my own gauge out of a Norma and did not have right set up to get threads straight enough, slight angle throws measurement off.I have had friends go by feel and it is really easy with bolt cam to over jam the bullet, seen that many times.