If your shell holder doesn't securely grip the sell and firmly fit into the press during reloading, you're bound to have headspace and sizing problems. RCBS manufactures their shell holders to the industry's tightest tolerances, using only the finest steel.

#2 Shellholder fits:
22 Savage High Power
25-35 Winchester
6.5mm x 55 Swedish Mauser
7-30 Waters
307 Winchester
7.5mm x 55 Schmidt-Rubin
7.7mm x 58 Japanese Arisaka
32 Winchester Special
32-40 Winchester
356 Winchester
375 Winchester
38-55 Winchester & Ballard