I had the same problem with my belgium browning 7mm rem mag when I had a new shilen barrel installed. even with my rcbs dies down tight my old brass would not go in to the new chamber and I thought I had a bad chamber job, as soon as I used new W-W brass the problem was solved. I still have 5 boxes of Browning 7mm rem mag brass in the fancy gold and black boxes sitting on my shelves ( this was 25 years ago) that I can not use. It was great Brass. As a side note it comes to me now after all these years there use to be a note from rcbs that some brass( norma and browning? ) took a # ( 26 or 28?) shell holder instead of the #4 and that is what I used for this brass so it must have been slightly different dimensions.
