.450 Bushmaster
Encyclopedia
The .450 Bushmaster is a rifle
cartridge
developed by Tim LeGendre of LeMag Firearms LLC, and licensed to Bushmaster Firearms International for production and distribution. LeGendre still retains ownership of the concept. The .450 Bushmaster is built on the XM-15 platform and designed to be used in the standard M16
and AR-15
platforms, using modified magazines and upper receiver assemblies.
Bushmaster asked 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". Bushmaster also requested a name change to ".450 Bushmaster", to which LeGendre agreed.
Based on the "Thumper" concept popularized by Jeff Cooper, the purpose of the cartridge was to provide guaranteed one-shot kills on big-game animals at 250 yards, using a large-bore (.44 cal or greater) cartridge in a semi-automatic rifle
.
Col. Cooper was not a fan of the M16/AR-15 system due to its use of the .223 Remington
/5.56x45mm NATO
cartridges.
The .450 Bushmaster is available in a 16 inch or 20 barrel. It uses a standard 20 round AR-15 magazine, with a different follower to create a five-round .450 Bushmaster magazine. The followers can be purchased through Bushmaster. The XM-15 platform (similar to an AR-15) controls the recoil of this heavy round. The rifle recoil is more like a push than the hit a user would expect from a regular rifle. Hornady and Remington both now manufacture ammunition for the rifle.
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. This rifle has a free floating barrel making it extremely accurate—it is capable of 1 MOA.
It comes with a A3 “Flat-top” upper receiver with Picatinny rail for sight/optics mounting convenience, allowing for the choice of the sight or scope to mount on it.
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...
developed by Tim LeGendre of LeMag Firearms LLC, and licensed to Bushmaster Firearms International for production and distribution. LeGendre still retains ownership of the concept. The .450 Bushmaster is built on the XM-15 platform and designed to be used in the standard M16
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
and AR-15
AR-15
The AR-15 is a lightweight, 5.56 mm, air-cooled, gas-operated, magazine-fed semi-automatic rifle, with a rotating-lock bolt, actuated by direct impingement gas operation. It is manufactured with the extensive use of aluminum alloys and synthetic materials....
platforms, using modified magazines and upper receiver assemblies.
Bushmaster asked the ammunition manufacturer Hornady
Hornady
Hornady Manufacturing Company is an American manufacturer of ammunition and handloading components, based in Grand Island, Nebraska.The company was founded by Joyce Hornady in 1949 and is currently run by his son Steve Hornady who took over after his father's death in a plane crash in 1981.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". Bushmaster also requested a name change to ".450 Bushmaster", to which LeGendre agreed.
Based on the "Thumper" concept popularized by Jeff Cooper, the purpose of the cartridge was to provide guaranteed one-shot kills on big-game animals at 250 yards, using a large-bore (.44 cal or greater) cartridge in a semi-automatic rifle
Semi-automatic rifle
A semi-automatic rifle is a type of rifle that fires a single bullet each time the trigger is pulled, automatically ejects the spent cartridge, chambers a fresh cartridge from its magazine, and is immediately ready to fire another shot...
.
Col. Cooper was not a fan of the M16/AR-15 system due to its use of the .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
/5.56x45mm NATO
5.56x45mm NATO
5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...
cartridges.
The .450 Bushmaster is available in a 16 inch or 20 barrel. It uses a standard 20 round AR-15 magazine, with a different follower to create a five-round .450 Bushmaster magazine. The followers can be purchased through Bushmaster. The XM-15 platform (similar to an AR-15) controls the recoil of this heavy round. The rifle recoil is more like a push than the hit a user would expect from a regular rifle. Hornady and Remington both now manufacture ammunition for the rifle.
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. This rifle has a free floating barrel making it extremely accurate—it is capable of 1 MOA.
It comes with a A3 “Flat-top” upper receiver with Picatinny rail for sight/optics mounting convenience, allowing for the choice of the sight or scope to mount on it.