Big-bore AR-15 cartridge developed at request of US Special Operations Command. Extreme close-range stopping power and barrier penetration in standard AR-15 platform.
Type: Rifle
Introduced: 2001, United States
Parent case: .50 AE
Standardization: Proprietary
Bullet diameter: 0.458" (11.63 mm)
Case length: 1.575" (40 mm)
Overall length: 2.26" (57.4 mm)
Max pressure: 35,000 PSI
Rim type: Rebated
Primer: Large Pistol
Typical twist rate: 1:14
Muzzle velocity: 1600–2050 fps
Muzzle energy: 2000–3000 ft-lbs
Effective range: 250 yd
Common bullet weights: 250, 300, 350, 400, 500 gr
Primary use: Military, Hunting, Self Defense
Production status: Active
Also known as: .458 SOCOM · 11.6x40mm
History: Developed in 2001 at the request of US Special Operations Command who wanted more stopping power than 5.56mm for close quarters battle. Designed to fit AR-15 platform with minimal modifications. Uses standard AR bolt face. Can load 10 rounds in standard 30-round magazine. Popular for hog hunting, dangerous game backup, and home defense. Competes with .50 Beowulf and .450 Bushmaster.
Notable firearms: AR-15 rifles and uppers, Rock River Arms LAR-458, Various custom AR builds
Similar cartridges: .50 Beowulf, .450 Bushmaster, .45 Raptor