Gunmagopedia: 450 Bushmaster

In the world of straight-walled cartridges, some are better known than others. Perhaps one of the most popular straight-walled options in the rifle world is the 450 Bushmaster, a cartridge that’s known for packing quite a punch whether on steel or while hunting. This cartridge has been around for some time and has a well-deserved following, but there’s always room for more. Consider this your one-stop for all things related to the history, specifications, and use of the 450 Bushmaster.


The Company Behind the Cartridge
450 Bushmaster Background
Did the military use the 450 Bushmaster?
Is the 450 Bushmaster a good long-range round?
Can the 450 Bushmaster be used for hunting?
Can the 450 Bushmaster be used for self-defense purposes?
450 Bushmaster specifications
Available loads for 450 Bushmaster
450 Bushmaster Firearm Manufacturers
Frequently Asked Questions

hornady ammo banner
While it was LeMag Firearms that designed the first iteration of 450 Bushmaster, Hornady fine-tuned it and took it commercial. (Photo credit: KSNB)


The Company Behind the Cartridge

This is another sizeable cartridge that technically owes its existence to the late Col. Jeff Cooper, the man who founded what is now known as Gunsite Academy in Paulden, Arizona. Cooper wanted a cartridge that carried a bit more weight behind it for hunting than the 5.56 NATO had to offer. His Thumper preferences — quite literally big rounds for big animals — are credited with inspiring the creation of quite a few larger caliber cartridges, including 450 Bushmaster. Of course, Cooper wasn’t the one who did the hands-on invention of the 450 Bushmaster. That credit goes to LeMag Firearms’ Tim LeGendre.

LeGendre invented the cartridge in 2007 under the title 45 Professional. His 45 Professional had most of the same specifications as what is now known as the 450 Bushmaster such as a .452 inch bullet diameter, but it did have a different case length. That change came about because when the 45 Professional became the 450 Bushmaster, it was at the hands of Hornady, the manufacturer LeGendre decided to work with for the commercial production of the cartridge.

When Hornady took on loading the ammo, they let LeGendre and Bushmaster know they wanted to shorten the case. This involved Bushmaster because that’s the firearms manufacturer LeGendre first worked with for an AR-15 chambered in the cartridge. Hornady told LeGendre and Bushmaster that the 450 Bushmaster would benefit from a case length shortened to 1.772 inches and an overall length reduced to 2.362 inches because it could better accommodate their SST flex-tip bullet. LeGendre and Bushmaster agreed, and the specifications of the 450 Bushmaster changed for the final time to be a bit shorter in general.

This is why when it comes to the creation of 450 Bushmaster, there’s more than just one company to consider. LeMag Firearms designed it, thanks to Tim Legendre, while Bushmaster created the first rifle chambered in it. Hornady created the final and quite popular specifications for the cartridge itself, and that is how 45 Professional became 450 Bushmaster. By 2009, the cartridge was SAAMI-approved and in production, and today there are numerous loads and loading components offered for it.


450 Bushmaster Background

According to the vision of the late Col. Jeff Cooper, the idea behind the 450 Bushmaster was to produce a cartridge capable of sending a 44 caliber—or larger—bullet down-range in an AR-15. This was a reasonable request and one with fantastic foresight when you consider how popular and widespread the AR-15 has become.

And while the 450 Bushmaster did indeed get its start being intended for hunting use, it’s branched out well beyond the hunting world. It’s an especially popular cartridge among AR-15 builders looking for a rifle build that shoots heavier bullets. Beyond that, it’s used for everything from plinking to home defense. Some gun owners even use their 450 Bushmasters as truck guns. It is a versatile cartridge.


Did the military use the 450 Bushmaster?

No, the 450 Bushmaster is not a military round. It’s true that it was designed as a more powerful option than the 5.56 NATO, which is used by the military, but that’s a tenuous connection at best. Realistically, the cost combined with the range limitations of the cartridge would make it a relatively poor choice for military use. Even so, it’s fantastic for the average hunter and shooter.


Is the 450 Bushmaster a good long-range round?

The 450 Bushmaster was not designed for long-range use, and that’s also not its strong suit. The exact reach of this straight-walled cartridge depends on the gun and ammo being used, but generally speaking, it drops fast past 100 to 150 yards. That makes it unsuitable for long-range shooting.

That said, you can certainly slingshot 450 Bushmaster onto steel targets at longer distances. It simply takes a familiarity with the specific load and gun being used. Of course, that means it’s not a good precision load for longer distances, but that’s fine. The 450 Bushmaster does exactly what it was intended to do, and it does it well.


Can the 450 Bushmaster be used for hunting?

Yes, 450 Bushmaster is an excellent option for hunting all manner of varmints, predators, and game animals. Thanks to the larger diameter of the bullet combined with the energy it produces, this cartridge is capable of dropping a wide range of animals quickly and effectively. As with any cartridge, it’s important to understand the distance limitations, but generally speaking, this is a reliable hunting round.

Deer hunters and feral hog hunters in particular tend to favor the 450 Bushmaster. Due to its best ballistic performance tending to be under 150 yards, it fits most deer hunting scenarios, and thanks to its phenomenal energy transfer on target it’s perfect for feral hogs. It can also be used for coyotes, badgers, bears, and just about any small to large game. There are some hunters who claim it’s great on moose and elk. It’s certainly possible, just be keenly aware of the specific performance abilities of the ammo you’re using (and remember to always respect shot placement).

If you’re using 450 Bushmaster to hunt it’s a good idea to pay attention to distance if you’re worried about meat loss. The .452-inch diameter bullet does create a substantial wound cavity, and if you’re taking a close-range shot at a deer, that might mean losing some meat you’d rather not see blown away. Even so, the meat loss tends to be negligible and not worth avoiding the cartridge altogether.


Can the 450 Bushmaster be used for self-defense purposes?

The 450 Bushmaster is commonly used for defensive applications, typically as a truck gun or for home defense. Its close-quarters capabilities are a big part of what makes some gun owners favor it for home defense while its versatility in smaller platforms makes it a favorite of some for use as a truck gun.

When used for home defense, or for self-defense in general, it’s a good idea to remember the energy the round produces. While any and all cartridges are capable of over-penetrating their targets, some are more prone to it than others, and the 450 Bushmaster is among them. This is simply another reason it’s important to familiarize yourself with your gun and ammunition. Also take into consideration the fact that certain bullets are designed to simultaneously slow down and expand, reducing the risk of over-penetration, while others are made to keep going. Your gear matters, and knowing how it works is a must when it comes to self-defense.

450 bm ammo
Hornady finalized the specifications of the 450 Bushmaster. (Photo credit: Hornady)


450 Bushmaster specifications

Name 450 Bushmaster
Designer LeMAG Firearms (Tim LeGendre)
Designed In 2007
Produced 2009-Present
Country of Origin United States
Variants None
Parent Case 284 Winchester
Case Type Straight Wall
Cartridge Type Centerfire Rifle
Bullet Diameter 0.452 inches
Neck Diameter 0.480 inches
Base Diameter 0.500 inches
Rim Diameter 0.4730 inches
Rim Thickness 0.0540 inches
Case Length 1.70 inches
Overall Length 2.260 inches
Case Capacity 59.5 gr H20
Primer Type Large Rifle
Maximum SAAMI Pressure 38,500 psi

Available loads for 450 Bushmaster

Thanks to the popularity of the cartridge there are quite a few loads available for it, made by a lot of different manufacturers. These are a few of our top picks for various purposes.

steinel ammo
There’s a lot of ammo available for the 450 Bushmaster, so whatever you use it for, there’s going to be a load for you. (Photo credit: Steinel Ammunition)

Hornady 250 grain FTX Hornady Black


  • High-quality cases manufactured to specific tolerances
  • Carefully selected and designed primers and propellants
  • Performance optimized
  • Made for superior fit, feed, and function
  • Designed for hunting medium and large game animals
  • Designed for self-defense applications
  • Ballistic coefficient of .210
  • Sectional density of .175
  • Impressive energy transfer on target

From Hornady: “Hornady BLACK ammunition features versatile loads optimized for excellent performance from America’s favorite guns. Loaded with legendary Hornady bullets, Hornady BLACK ammunition is designed to fit, feed and function in a variety of platforms.”

Distance (yards) Velocity (feet per second) Energy (foot-pounds) Trajectory (inches)
Muzzle 2200 feet per second 2686 foot-pounds -2.0 inches
100 yards 1835 feet per second 1868 foot-pounds 4.1 inches
200 yards 1515 feet per second 1274 foot-pounds 0
300 yards 1255 feet per second 874 foot-pounds -19.3 inches

*The table above was generated using a 20-inch barrel.

Winchester Deer Season XP 250 grain Extreme Point Polymer Tip

Winchester deer season ammo
This load is specifically made for deer hunting and performs exceptionally well. (Photo credit: Winchester)


  • Polymer tip for reliable expansion and improved overall ballistics
  • Larger diameter polymer tip than similar designs for creation of larger wound cavities on target
  • Jacket contoured for superior terminal performance
  • Alloyed lead core for improved energy transfer on target
  • Designed for accuracy
  • New brass cases can be reloaded
Distance (yards) Velocity (feet per second) Energy (foot-pounds) Trajectory (inches)
Muzzle 2200 feet per second 2686 foot-pounds Not available
100 yards 1834 feet per second 1867 foot-pounds 4.5 inches
200 yards 1514 feet per second 1272 foot-pounds 0
300 yards 1254 feet per second 873 foot-pounds -19.8 inches

From Winchester: “Deer Season XP combines decades of Winchester experience into the perfect choice for deer hunting ammunition. Accuracy, combined with massive bullet impact performance means that Deer Season XP is a great choice for all deer hunters. Suitable for use on Whitetail, Mule and Blacktail Deer.”

Federal Premium PowerShok Rifle 300 grain Jacketed Hollow Point

Federal ammo 450 bushmaster
Federal PowerShok is well known among hunters and this load does not disappoint. (Photo credit: Federal Premium)


  • Consistent shot-to-shot performance
  • Proven performer on a variety of varmints and game animals
  • New brass cases can be reloaded
  • Bullets designed for impressive expansion and weight retention
  • Accurate on target
  • Superior energy transfer thanks to ballistics and bullet weight
  • Ballistic coefficient of .225
  • Terminal performance minimum velocity is 1000 feet per second
Distance (yards) Velocity (feet per second) Energy (foot-pounds) Trajectory (inches)
Muzzle 1900 feet per second 2405 foot-pounds 0.7 inches (50 yards)
100 yards 1592 feet per second 1687 foot-pounds 0
200 yards 1331 feet per second 1179 foot-pounds -12.4 inches
300 yards 1136 feet per second 860 foot-pounds -44.5 inches
400 yards 1014 feet per second 685 foot-pounds Not available
500 yards 932 feet per second 579 foot-pounds Not available

From Federal Premium:

  • The only tag these loads won’t fill is the price tag. The traditional lead-core hunting bullets in Federal PowerShok rifle loads provide solid accuracy and power at an affordable price. They feature reliable Federal brass, primers and powder and are suited to a wide variety of medium and big game.
  • Federal PowerShok is hard hitting ammunition designed for exceptional performance in the field. The only tag these loads won’t fill is the price tag. The traditional lead-core hunting bullets in Federal Power-Shok rifle loads provide solid accuracy and power at an affordable price. They feature reliable Federal brass, primers and powder and are suited to a wide variety of medium and big game. A combination of premium bullets with Federal’s reputation for quality results in a hunting round that you can depend on. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.

Barnes VOR-TX 250 grain TSX

barnes 450 bm
Barnes VOR-TX 450 BM 250 grain TSX features an all-copper bullet and performs impressively on game animals. (Photo credit: Barnes)


  • Designed for fantastic ballistics
  • Devastating energy transfer on target
  • Made to create large wound cavities for a quick, ethical shot
  • All-copper bullets are lead free
  • Created for superior weight retention which translates to larger wound cavities and greater energy transfer
  • New brass cases can be reloaded
  • Ballistic coefficient is 0.2
Distance (yards) Velocity (feet per second) Energy (foot-pounds) Trajectory (inches)
Muzzle 2200 feet per second 2686 foot-pounds -2.5 inches
100 yards 1811 feet per second 1821 foot-pounds 0
200 yards 1469 feet per second 1198 foot-pounds -8.8 inches
300 yards 1206 feet per second 807 foot-pounds -33.7 inches

From Barnes: “Loaded with the Barnes Triple-Shock X (TSX) Bullet, this round offers devastating results on varmints. The Barnes TSX bullet is made of 100% copper and contains no lead. When the bullet expands, four razor-sharp cutting petals are created, allowing the bullet to penetrate farther through tough bone and tissue. These bullets usually retain 100% of their original weight. The Triple-Shock X bullet delivers the “three strikes you’re out” rule. Once as it strikes game, two as the bullet begins to open and a third impact when the cavity fully expands to deliver extra shock with maximum transferred energy. Ideal for deer-sized game.VOR-TX ammunition is manufactured to precise tolerances to ensure excellent accuracy and consistent velocities. This ammunition is new production, non-corrosive, in boxer-primed, reloadable brass cases.”

Remington Premier AccuTip 260 grain

remington accutip ammo
This is a fantastic hunting round. (Photo credit: Remington)


  • AccuTip delivers fantastic accuracy on target
  • Polymer tip aids in expansion and keeps nose of bullet free of foreign material
  • Designed for use on medium to large game animals
  • Effective on varmints and predators
  • New brass cases can be reloaded
  • Ballistic coefficient of .144
Distance (yards) Velocity (feet per second) Energy (foot-pounds) Trajectory (inches)
Muzzle 2180 feet per second 2743 foot-pounds 3.3 inches (50 yards)
100 yards 1665 feet per second 1600 foot-pounds 5.7 inches
200 yards 1261 feet per second 918 foot-pounds 0
300 yards 1026 feet per second 608 foot-pounds -28.0 inches
400 yards 903 feet per second 471 foot-pounds -87.6 inches
500 yards 816 feet per second 384 foot-pounds -186.4 inches

From Remington: “One seriously lethal hunting tip. From its polymer tip, to its lead core, Premier AccuTip is optimized for match-grade accuracy and stunning on-game performance. Thousands of rounds in development, it combines truer flight, flatter trajectory and devastating terminal energy. No wonder it’s the consistent choice of serious hunters the world over.”


450 Bushmaster Firearm and Barrel Manufacturers

atheris rifle in 450 bm
The 450 BM was originally made for the AR-15 platform. (Photo credit: Atheris Rifle Company)

The cartridge was originally meant for the AR-15 platform, but it’s since been used in other platforms as well. We’ve broken down the popular firearms manufacturers by platform to give you a better idea of who’s making 450 Bushmasters you might be interested in checking out.

AR platform rifles and pistols:

  • Windham Weaponry
  • Atheris Rifle Company
  • Alex Pro Firearms
  • GLFA
  • Rock River Arms
  • Bushmaster
  • Franklin Armory
  • Radical Firearms
  • American Tactical
  • Bear Creek Arsenal

Bolt-action rifles:

  • Ruger
  • Remington
  • Savage Arms
  • Christensen Arms
  • Bergara
  • Howa
  • Mossberg

Single-shot rifles:

  • Traditions
  • CVA
  • Henry Repeating Arms

Barrels for 450 Bushmaster

If you’re interested in building your own 450 Bushmaster, it can help to get an idea of which companies are manufacturing barrels (among other things). These are a few of the manufacturers producing 450 Bushmaster barrels:

  • Bear Creek Arsenal
  • Faxon Firearms
  • Hitman Industries
  • Rock River Arms
  • Christensen Arms
  • Wilson Combat
  • Next Level Armament


Frequently Asked Questions

windham weaponry rifle
The 450 Bushmaster has a lot to offer and is especially popular in the AR-15. (Photo credit: Windham Weaponry)

When was the 450 Bushmaster designed?

The cartridge was designed in 2007.

What’s the 450 Bushmaster’s parent cartridge?

The 284 Winchester is the 450 Bushmaster’s parent cartridge.

What’s the 450 Bushmaster’s bullet diameter?

It has a bullet diameter of .452 inches.

Is it good for deer hunting?

Yes, this cartridge is popular among deer hunters.

What’s the effective hunting range of 450 Bushmaster?

Generally, the cartridge is effective on game animals out to about 150 yards. As some ammunition manufacturers note, terminal velocity for this round is approximately 1000 feet per second and above.

Is this a self-defense round?

Yes, it can be used for self-defense purposes.

What company invented 450 Bushmaster?

The 450 Bushmaster was originally created by LeMag Firearms and was then shortened a bit and commercially produced by Hornady.

When did the cartridge go into production?

It has been in production since 2009.

What is a Thumper round?

The late Col. Jeff Cooper often talked about his Thumper concept which revolved around the idea of heavier, harder-hitting cartridges than what was available decades ago. For example, the design of the 450 Bushmaster was based on Cooper’s desire for a cartridge with a 44 caliber or heavier bullet that could be fired from an AR-15 for hunting purposes.

Can you build your own 450 Bushmaster?

Yes, it is possible to build your own rifle chambered in 450 Bushmaster. There are enough components on the market to make this not only possible but easy to accomplish.

What is the overall length of 450 Bushmaster?

It has an overall length of 2.260 inches.

How hard does a gun chambered in 450 Bushmaster recoil?

Felt recoil depends on a few factors such as the design of the gun being used and the specifics of the load being fired. That said, 450 Bushmaster tends to produce approximately 27 foot-pounds of felt recoil, meaning it does have significant felt recoil.

What can the cartridge be used for?

The cartridge was first created for hunting and that remains the area in which it performs its best. It’s also used for plinking and home defense.

What’s the effective range of 450 Bushmaster on steel?

The drop rate for the 450 Bushmaster is rather substantial beyond 200 yards so although it’s possible to hit steel at longer distances, it becomes a lot more challenging due to its precipitous drop rate.

Who invented 450 Bushmaster?

Tim LeGendre of LeMag Firearms invented it in 2007. He originally called it the 45 Professional.

Is there a 450 Bushmaster handgun?

Yes, there are some handguns chambered in 450 Bushmaster. One is the Magnum Research BFR, which is a heavy-duty revolver.

Is 450 Bushmaster better than 45-70 Government?

Both cartridges produce similar ballistics, but they aren’t identical. They also can’t really be compared well because the 450 Bushmaster was designed for the AR-15 while the 45-70 Government was made for the lever-action rifle.

Is it a straight-walled cartridge?

Yes, it is a straight-walled cartridge. That means it can be used in restrictive states where certain bottleneck cartridges cannot be used. Because it can be used in more states than some other cartridges can be, it’s become increasingly popular among deer hunters.

How much energy does the 450 Bushmaster produce?

The muzzle energy of many, if not most, 450 Bushmaster loads is 2000 foot-pounds and above. However, it does lose energy quickly which limits its effective range. At closer distances, though, the energy transfer is enormous.

Can you handload the 450 Bushmaster?

Yes, the components are available to handload or reload 450 Bushmaster. Just take care to adhere to SAAMI specifications.

What is the bolt face size of the 450 Bushmaster?

It has a bolt face size of 0.473 inches.

Kat Ainsworth Stevens is a long-time outdoor writer, official OGC (Original Gun Cognoscenti), and author of Handgun Hunting: a Comprehensive Guide to Choosing and Using the Right Firearms for Big and Small Game. Der Teufel Katze has written for a number of industry publications (print and online) and edited some of the others, so chances are you've seen or read her work before, somewhere. A woman of eclectic background and habits, Kat has been carrying concealed for over two decades, used to be a farrier, and worked for a long time in emergency veterinary medicine. She prefers big bores, enjoys K9 Search & Rescue, and has a Master's Degree in Pitiless Snarkastic Delivery.

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