I had the same problem, not only with 7x57 S&B but also older Winchester brass - I ended up using a RCBS #11 shell holder which is listed as the alternate from the #3.
Type: Posts; User: Basenjiboy
I had the same problem, not only with 7x57 S&B but also older Winchester brass - I ended up using a RCBS #11 shell holder which is listed as the alternate from the #3.