Buy yourself a case gauge from Dillon, Brownells, or other places to set up your press with. I've done this with 5.56 and 7.62 just to be on the safe side. Wilson 7.62/.308 gauge & Dillon 5.56 case. Use some imperial sizing die wax to lube cases and resize until they fit properly into the case gauge. Use cleaned fired cases and not new cases to do this. I have had new cases undersize. Good luck. Reloading supplies may come back in the near future, just have every thing ready when they do.