I had a similar situation after having my 204R re-barreled. I sent my sizing die to the smith that did the no-nut barrel install and he trimmed it ten thou. That fixed it. Also had a similar situation with my 6.5x55AI. This time I had set the barrel up with a go guage and tape on the end for no go. Instead of trimming the die I just modified my shell holder. Works the same as trimming the die.