RCBS Small Base Sizer Die 2 Die Set 308 WinchesterRCBS Small Base 2 Die sets are useful for reloaders loading for semi automatic, pump action and lever action rifles to help ensure that proper functioning. Small base sizing dies size brass to minimum specifications and help to ensure that cartridges will chamber every time. Due to the fact that this product sizes more than regular dies, it is crucial to have a sufficient amount of high quality lubricant to prevent stuck cases. Technical Information