SINCLAIR 749-011-472 SHOULDER BUMP GAGE INSERT. For cartridge cases; 22-250 Remington, 223 & .243 WSSM (Winchester Super Short Mag), & other cases up to 6.5mm with 28° shoulder. Used to measure the amount of shoulder bump when setting up sizing die. Bump gage is the most accurate when used on the granite surface plate of our Ultimate Cartridge Check System. Recommended bump of .001 to .002 shoulder setback for bolt actin guns and .005 for Semi-Auto and other repeating actions. POSTPAID!