RCBS Matchmaster Comp Seat Die 338 ARCRCBS Matchmaster Comp Seat Die 338 ARC Includes 1 bullet seating die; Micrometer adjustable bullet seating depth; Free floating, self centering bullet seating stem for accuracy; Bullet loading window for easy alignment and seating; Bullet retaining system ensures proper alignment during seating; Thread size: 7 8" 14; Storage box included; Shellholder not included; Made in the United States of America; Available in sizes: 223 REM, 300 PRC, 300 Win Mag,