RCBS pioneered and developed 3-Die Sets for straight-wall rifle and pistol cases. The Carbide Sizer Die sizes the case and de-primes (the carbide sizer ring eliminates the need to lubricate). The Expander Die expands the case to the proper diameter to accept the bullet, and it imparts case mouth flare/bell for bullet feeding. The Seater Die seats the bullet and taper crimps.
Specifications:

Type
Caliber	44 Auto Mag
Die Type	Expander/Taper Crimp Seat
Die Series	Straight Walled Cartridges
In Set	3
Metal Type
Adapt to Mfg
Shell Holder Cap
Shell Holder Cap