I just received a "Y" Model 12 Trap I purchased and it will not fully chamber my Remington STS reloads, so it will not fire. It scratches the front part of the brass and it feels like there is a constriction in the chamber. Is this something a gunsmith can polish out ? I have never experienced this with any other shoguns I own, including my "Y" Model 12 skeet gun using my reloads so I am not willing to adjust my Dillon SL900. It will chamber new STS and AA shells. I have a 3 day inspection and the seller has agreed to let me return the gun.