I just had a rifle built with a PacNor 250 Ackley Improved barrel. I've fire formed about twenty rounds of Rem-UMC 250 Savage ammunition with no real issues and I've reloaded them using RCBS dies and all seems well. I also acquired about 20 loaded rounds and 5 fired 250 AI cases made from Nosler 22-250 brass. These are causing me some trouble, however. Neither the Nosler reloads nor the fired cases will chamber in my rifle. The bolt will not close on the round. I tried resizing one of the fired Nosler cases with the RCBS 250 AI dies and the bolt will still not close on the resized case. I was hoping that I could use 22-250 brass to reload to 250 AI but now I'm not sure I can. Any idea of what is the matter?