This is an RCBS Double Cavity Cast Bullet Mould #82090 casting a .378" nominal diameter, 312 grain bullet, designation 378-312-BPS (BPS=Black Powder Silhouette), good for 38-55 Winchester caliber, uses RCBS Top Punch #608, Item #RCB85608. Approximate Bullet Dimensions: Bullet Length-1.34", Nose Length-0.72".