X-Treme Bullets 357 Sig Caliber Pistol Bullets 124 Grain X-DEF Hollow Point 100 Bullets. X-Treme Bullets process starts with a lead billet that is extruded into wire. The lead wire is then swaged into a core. The cores are copper plated then restruck once more. Though not common in the industry this restrike process produces a bullet that is more uniform with a more precise diameter and a smoother finish for a better shooting and better looking bullet. Specifications for X-Treme Bullets 357 Sig Caliber Pistol Bullets 124 Grain Hollow Point: Manufacturer: X-Treme Bullets Bullet Type: Hollow Point (HP) Caliber: .357 SIG Cartridge Type: Brass Bullet Weight: 124 grain Diameter: 0.429 in Core Material: Lead Jacket Material: Copper Bullet Quantity: 100 Bullet Package Contents: X-Treme Bullets Pistol Bullets .38 Caliber 158 Grain Hollow Point X-Treme Bullets 357 Sig Caliber Pistol Bullets 124 Grain X-DEF Hollow Point 100 Bullets