RCBS Small Base Sizer 308 Winchester 15531

The 308 Winchester Small Base Sizer from RCBS is a full length sizing die that yields dimensions below SAAMI minimum.  Full length sizing to tight dimensions is sometimes required when using cartridge cases fired in a rifle with a different chamber.  In some instances a regular full length die will not make the sized case small enough to fit in a tight 308 Winchester chamber and will require a small base die.  Cases must be properly lubricated prior to sizing using this or any other sizing die.

This sizing die full length sizes the entire case, including the neck.  Should you desire a die that only sizes the case body and shoulder you should choose a small base body die instead.

Some target rifles have very tight chambers and will require the use of a small base die on a regular basis.  Semi Auto and other rifles that depend on spring pressure to close the bolt may feed more reliably with the use of small base dies.