Bushmaster .450
Bushmaster Firearms International · Rifle · In Production · 2007
Also known as: Bushmaster XM-15 E2S .450, Bushmaster Thumper
Overview
The Bushmaster .450 is a Bushmaster XM-15 / M4-pattern semi-automatic AR-15 rifle chambered in the .450 Bushmaster cartridge. The cartridge was designed by Tim LeGendre of LeMag Firearms and licensed to Bushmaster, originally inspired by Jeff Cooper's 'Thumper' concept of a hard-hitting brush rifle on the AR-15 platform. Standard configurations use a 20-inch chrome-lined 4150 chrome-moly steel barrel with 1:24 twist, a 5-round single-stack magazine, and an A2-style fixed stock; a 16-inch carbine variant is also produced.
Specifications
| Weight (empty) | 3765 g (132.8 oz) |
| Overall Length | 1003 mm (39.49") |
| Barrel Length | 508 mm (20.00") |
| Action Type | Gas Operated Long Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Trigger Pull | 31 N (7.0 lbf) |
| Magazine Capacity | 5 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 671 m/s (2201 fps) |
| Muzzle Energy | 3641 J (2685 ft·lbf) |
| Effective Range | 250 m (273 yd) |
| Maximum Range | 1800 m (1968 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 610 mm (24.02") |
| Number of Grooves | 6 |
| Frame Material | Aluminum |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Black Anodized |
Calibers
- .450 Bushmaster · primary — also known as 11.48x43mmRB, 450 BM
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety, Ar15 Safety Selector
- Features: Ar15 Platform Compatible, Flat Top Upper, Picatinny Rail, Chrome Lined Bore, A2 Flash Hider, Fixed A2 Stock
Variants
Service history
Operators
- United States civilian market · adopted 2007
Production
Production years: 2007-present
Civilian sporting rifle; popular for straight-wall cartridge deer hunting in U.S. Midwestern states
Origin
Country of origin: United States
Designer: Tim LeGendre
Notes
The .450 Bushmaster cartridge designation under European CIP is 11.48x43mmRB. Production briefly paused after Remington Outdoor's 2020 bankruptcy but resumed under new ownership.
Background
The .450 Bushmaster grew out of Col. Jeff Cooper's 'Thumper' idea: a one-shot stop on man-sized targets out to 250 yards from an AR platform. Tim LeGendre's original design used a longer case until Hornady shortened it for production, and the cartridge later exploded in popularity when Michigan, Indiana, and Ohio legalized straight-wall rifle cartridges for deer.