savage 6x45 build

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?

When I built mine I tried using the brass to head space with,I ended up getting a go gauge and ended my problems.If you don't have access to one let me know and I will loan you one

Ok sounds good to me. Pm sent