This is a RCBS , model 11129.
The Full-Length Sizer Die brings the case to SAAMI minimum cartridge dimensions. It sizes the outside of the case" de-primes and expands the neck to accept the bullet. The die has vents to prevent case damage caused by trapped air and for excessive lubricant. Headspace is held to minimum tolerances to avoid changing the case body length during full length sizing.
Features:
De-primes and expands the neck
Sizes the outside of the case
