just got my savage build finally pieced together and head spaced it using once fired 223 military brass full length sized it using my 6x45 RCBS small base sizer die. My question is should I be using a head space go gauge instead of using brass? I then switched and chambered some lake city brass and when the bolt closes on it is very tight and wont chamber properly. Will I be better off setting it to factory SAAMI spec so I can chamber various different types of brass? what do you all think?