Knights Armament SR-15 E3 Mod 2
Knight's Armament Company · Carbine · In Production · 2015
Also known as: KAC SR-15, SR-15 Mod 2, E3 Mod 2
Overview
The Knights Armament SR-15 E3 Mod 2 is a semi-automatic carbine chambered in 5.56x45mm NATO, produced by Knight's Armament Company since 2015. Featuring a 30-round magazine capacity, this carbine offers generous firepower for duty use and home defense.
Specifications
| Weight (empty) | 2858 g (100.8 oz) |
| Weight (loaded) | 3428 g (120.9 oz) |
| Overall Length | 813 mm (32.01") |
| Folded Length | 813 mm (32.01") |
| Barrel Length | 368 mm (14.49") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Two Stage |
| Trigger Pull | 20 N (4.5 lbf) |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 930 m/s (3051 fps) |
| Muzzle Energy | 1730 J (1276 ft·lbf) |
| Effective Range | 550 m (601 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Hard Anodized |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as 5.56mm NATO, 5.56x45mm, .223 Remington
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety Selector, Half Cock Notch
- Features: Ambidextrous Controls, Ambidextrous Bolt Release, Ambidextrous Magazine Release, Urx 4 Mlok Handguard, Chrome Lined Barrel, Chrome Lined Chamber, E3 Round Lug Bolt, Two Stage Trigger, Mid Length Gas System, Free Float Barrel, Improved Bolt Design, Extended Bolt Life
Variants
- SR-15 E3 Mod 2 16" — Standard Barrel
- SR-15 E3 Mod 2 11.5" — Short Barrel
Service history
Operators
- United States Special Operations Forces · as SR-15
- Law Enforcement (Various) · as SR-15 E3 Mod 2
Production
Production years: 2015-present
Production quantities not publicly disclosed; limited commercial availability due to military contracts
Origin
Country of origin: United States
Designer: C. Reed Knight Jr.
Notes
The SR-15 E3 Mod 2 is Knight's Armament's semi-automatic commercial offering, while their SR-16 represents the full-auto military counterpart. The E3 bolt design is a significant engineering achievement, featuring improved locking lugs that distribute stress more evenly and resist wear. The mid-length gas system is specifically tuned to the 14.5-inch barrel length for optimal cycling with both suppressed and unsuppressed configurations. Knight's relationship with U.S. Special Operations Forces means every design decision is informed by real combat experience. The URX 4 rail system uses M-LOK mounting instead of traditional Picatinny, reducing weight while maintaining rigidity. Upper receiver groups return to zero when reinstalled, making barrel changes practical for field maintenance or caliber conversion.
Background
Knight's Armament Company founder C. Reed Knight Jr. revolutionized the firearms industry by focusing exclusively on feedback from the world's most elite special operations units. The SR-15's development was directly influenced by decades of working alongside Navy SEALs, Army Special Forces, and Delta Force operators, resulting in a rifle that represents the absolute state-of-the-art in AR-15 design.