.450 Bushmaster

.450 Bushmaster
Type Rifle
Place of origin  United States
Production history
Designer LeMAG FIREARMS LLC
Manufacturer Bushmaster/Hornady
Specifications
Parent case .284 Winchester
Case type Rebated rim, Straight wall
Bullet diameter .452 in (11.5 mm)
Neck diameter .473 in (12.0 mm)
Case length 1.700 in (43.2 mm)
Maximum pressure (SAAMI) 40,000 psi (280 MPa)
Ballistic performance
Bullet weight/type Velocity Energy
250 gr (16 g) SST 2,214 ft/s (675 m/s) 2,722 ft·lbf (3,691 J)
260 gr (17 g) AccuTip 2,180 ft/s (660 m/s) 2,744 ft·lbf (3,720 J)
Test barrel length: 20 in (508 mm)
Source(s): Hornady & Remington[1]
The 450 Bushmaster was developed for big game hunting with modern rifles.

The .450 Bushmaster is a concept rifle cartridge, developed by Tim LeGendre of LeMag Firearms, and licensed to Bushmaster Firearms International. The .450 Bushmaster is designed to be used in the standard M16 and AR-15 platforms, using modified magazines and upper receiver assemblies.

History

The .450 Bushmaster is descended from the "Thumper" concept popularized by gun writer Jeff Cooper. Cooper was dissatisfied with the small-diameter 5.56x45mm NATO (.223 Remington) of the AR-15, and envisioned a need for a large bore (.44 cal or greater) cartridge in a semi-automatic rifle to provide one-shot kills on big-game animals at 250 yards. Inspired by this, LeGendre developed his .45 Professional cartridge, and later built and delivered an AR-15 in .45 Professional to Cooper.[2]

Bushmaster requested the ammunition manufacturer Hornady to produce the .45 Professional cartridge for this project, but Hornady wanted to shorten the cartridge case to accommodate their 0.452" 250-grain pointed SST Flex-Tip bullet. Bushmaster and LeGendre approved the change from 1.771" to the now-standard 1.700", and a name change to ".450 Bushmaster".

Loadings and ballistics

The .450 Bushmaster uses standard .458 diameter bullets offerings swaged down to .452". The .450 Bushmaster is a high-pressure rifle case, thus making efficient use of heavy .452" bullets. The cartridge is chambered in AR-15 rifles, as well as an AR-15 pistol by Franklin Armory.[3]

Ballistically the round is very flat out to 200 yards; if the firearm is zeroed at 150 yards, the user can expect to see a rise of 1.8 inches at 100 yards, zero at 150 yards and a drop of 2.4 inches at 200 yards. Magazine capacity can be either five-round or nine-round depending on the magazine body used. A 20-round AR-15 magazine body will yield a five-round magazine, whereas a 30-round body will yield a 9-round magazine. Hornady and Remington both now manufacture ammunition for the rifle.

See also

References

  1. ↑ PREMIER® ACCUTIP™ 450 BUSHMASTER Remington Arms Company
  2. ↑ Frank C. Barnes (5 October 2012). Cartridges of the World: A Complete Illustrated Reference for More Than 1,500 Cartridges. Gun Digest Books. pp. 97–. ISBN 1-4402-3059-5.
  3. ↑ Pridgen, D.K. "FRANKLIN ARMORY XO-26 .450 BUSHMASTER". Tactical-Life Magazine. Retrieved 26 Feb 2014.

External links