[Unclenick]

DON'T! Not even if you can. It may just be a scuff from the case mouth ramping up the shoulder and into the neck recess in the chamber, but you need to check that first. If that case mouth actually wedges into the start of the freebore, it can raise pressure substantially by preventing the release of the bullet from occurring at its normal point in the powder burn curve. I would definitely do a chamber cast at this point. If the chamber's neck recess is longer than the necks of your cases, then that is just a chambering scuff. If it is equal to or shorter than your necks, you need to trim your cases back 0.02" or get a properly dimensioned reamer run in there. It's not unheard of for newer cartridge designs to result in some initial reamer dimensioning discrepancies between reamer suppliers.