While “Big Bore” mania has been circulating for a while now, a newer cartridge is finding its way to the head of the popularity pack: The .450 Bushmaster.
If you want a closer look at the history behind this powerful cartridge, its specifications, who it’s for and how to build a .450 Bushmaster rifle, then you’ll love this article.
Let’s get started!
History of the .450 Bushmaster
When Col. Jeff Cooper, a United States Marine who fought in WWII and the Korean War, was in the heat of battle, he needed rounds he could depend on for powerful, armor-piercing shots and deadly accuracy.
The rounds commonly used by military forces at the time just weren’t enough for him.
So, when he got back home, Cooper came up with the idea of a cartridge similar to the one found in his .45 ACP pistol that would work for a wider variety of firearms.
LeMag Firearms took his idea and ran with it, creating the .45 Professional cartridge that was later turned over to Hornady so that they could mass-produce the cartridges for Bushmaster’s AR-15 rifles.
It was dubbed the .450 Bushmaster.
The .450 Bushmaster wasn’t widely used until recently, and now, the round is being produced by major manufacturers including Federal, Buffalo Bore and Remington.
Why the sudden interest?
A relatively new change in gun laws makes it so that hunters in the Midwest can now use straight-walled cartridges in their semi-auto weapons.
A posse of medium-game hunters that were itching to use their AR’s flocked to ammo shops and many ended up choosing the .450 Bushmaster because of its reasonable price.
Now, the .450 BM is one of the most popular straight-walled cartridges on the market.
.450 Bushmaster Specifications
The .450 Bushmaster’s dimensions come in just under maximum legal limits, maximizing power and distance.
Here are the specifications:
- Rim diameter: .453 inches
- Overall length: 2.25 inches
- Shell-case length: 1.7 inches
- Bullet sizes: Between 245 and 300 grains.
- Muzzle velocity: 2,200 ft/s, 200-yard velocity at 1,500 ft/s.
- Muzzle energy: 2,700 ft/lb, 200-yard energy at 1,200 ft/lb.
This cartridge packs a serious punch, but what about its range?
Bushmaster .450 Effective Range
With as much energy as this cartridge generates, you’re going to get a larger range.
I found this was definitely true for the .450 Bushmaster that was giving me between 1.5 and 2.5-inch groupings at 100 yards.
That was a lot more accurate than my .45-70’s were getting.
Pace that out to 200 yards, and I was still getting some great accuracy. 300 yards is about the max range for this cartridge as it will start seriously dropping.
The optimal conditions for longer-range shots would be shooting from a stand during mild, windless weather.
Building a .450 Bushmaster Rifle
If you’ve already got a standard-built AR-15, then you’ve got half of a .450 Bushmaster rifle in your hands.
With a few tweaks to the upper assembly, I created a killer weapon that wasn’t too hard on the wallet.
The next (and MOST IMPORTANT) thing I did was change out the mags.
If you don’t do this, you can get some massive misfeeds and a lot of headaches. Lancer mags seem to work well — especially if you throw on some Tromix followers.
Boom. Now you’ve got a completely operable .450 Bushmaster rifle with minimal effort.
You WILL want to fit your rifle with some sort of muzzle device if you want to keep your shoulder in working order.
I like the Precision Armament Hypertap because it effectively mitigates the powerful blast generated by .450 BM.
If you don’t already own an AR and still want to get in the .450 game, I highly recommend the Ruger American Rifle Ranch that is already set up and ready to go for .450 Bushmaster cartridges.
Why Use the .450 Bushmaster?
There are several reasons I got into shooting .450 Bushmaster.
But the main reason ended up being the fact that I could use this cartridge in places that I couldn’t use traditional bottlenecks.
It’s great for clean, quick and humane kills on medium-sized game like deer, elk, hogs and some bears.
It deftly out-performed the .350 Legend at the 250 to 300-yard range.
It also maintains much greater downrange energy than other rounds like the .223 Remington, which makes the .450 Bushmaster a great choice for competitive shooting as well as hunting.
The .450 BM is also very reasonably priced.
Overall, this newly-popular round is exceptional at getting your shot further downrange with maximum power.
Here are some of the highlights:
- Legal for more areas
- 250 to 300-yard effective range
- Easy to build from an already-owned AR-15
So, if you’re looking to blast a hog, take down a deer across the field, or place in the top scorers at competition, you don’t want to overlook the .450 Bushmaster.
Have you tried the .450 Bushmaster cartridge? What did you think of it? Let us know in the comments below!