Unlike conventional fmj bullets that leave lead exposed at the base, speer uses uni-cor technology to completely encase the tmj bullets lead core in a seamless jacket.Its cleaner, more accurate and more consistent than any fmj.Coefficient: .173Bullet Type: Total Metal Jacket (TMJ)Bullet Diameter: .357Weight: 158 grBullet Caliber: 38 CaliberJacket Material: CopperCore Material: LeadCannelure: YesSectional Density: .177Quantity: 100 Per BoxRecommended Usage: Target