I’ve always been a bolt-action rifle guy and, admittingly was a semi-auto curmudgeon regarding big-game hunting rifles. Then, during the late winter of 2020, a trip to the Lone Star State with some of my best hunting amigos altered my mindset. That’s when I met the 450 Bushmaster.
Aoudad and hogs were on the menu, and my companions and I had over 6,000 acres of free-range Texas Hill Country to roam. I rolled my eyes when my buddy, Jeremiah, pulled an AR-15 chambered in 450 Bushmaster from his gun case. The shots on the aoudads were sure to be long, and looking at the beefy, big-nosed cartridges he was loading into the magazine, I thought he’d made a poor choice.
From .45 Professional to 450 Bushmaster
The 450 Bushmaster was developed by the late gunsmith Tim LeGendre and his company LeMag Firearms in the early 2000s. In a 2015 interview with The Gun Smith Show, LeGendre described the 450 Bushmaster as “a high-performance AR-15.”
As the story goes, LeGendre designed the cartridge using the “thumper” concept introduced by the late shooting instructor and father of the modern handgun technique Jeff Cooper. The concept was based on Cooper favoring big-bore rifles that could kill an animal or man with one shot over small-bore rifles, which could hold more ammo. Where LeGendre and Cooper’s visions diverge is the guns Cooper favored traditionally used a bolt action, and LeGendre wanted to apply the concept to a semi-automatic rifle.
LeGendre started with the cartridge. He modeled the 450 Bushmaster off of the .284 Winchester, a long-range round designed for semi-auto and lever-action rifles. What he did was modify the casing so it could fit a .45-caliber bullet, which resulted in a straight-walled cartridge. Then, he fitted an AR-pattern rifle with a larger-diameter barrel.
Although he initially called the cartridge .45 Professional, he eventually partnered with Bushmaster to produce the rifles and Bushmaster partnered with Hornady to produce the ammo. But today, a wide variety of manufacturers produce both guns and ammo.
LeGendre explained that Cooper hated AR-15 rifles, but when he was impressed with the 450 Bushmaster. “He saw what I was doing to it, and he said, ‘I could now own one,’ and I built two of them for him,” LeGendre said. With Cooper’s blessing and the cartridge’s overall performance, the 450 Bushmaster earned the nickname “thumper.”
There are many types of 450 Bushmaster bullet builds, from soft points to jacketed hollow points to plastic-tip designs, and most offerings range in grain weight between 180 and 350 grains. Heavy for sure, but the idea 450 Bushmaster ammo manufacturers are going for is a short- to medium-range round that drops velocity quickly due to low muzzle velocities and low BC bullets but hits like a freight train.
Muzzle velocity also varies by grain weight, but for common weights like 250 to 300 grains, it averages out to around 2,000 fps. The thing to remember is the foot-pounds of energy these high-grain-weight lower velocity bullets provide at short distances. For example, Winchester’s 250-grain Deer Season XP delivers roughly 2,687 foot-pounds of energy.
And polymer-tipped bullets will spice things up even more. For instance, Hornady’s Black guarantees great cycling and efficiency, and the FTX bullet with a polymer tip gives the shooter a more comprehensive range.
This was the bullet choice of my buddy Jeremiah, and I watched with awe as he destroyed a group of feral hogs at distances between 87 and 167 yards. His AR-15 450 Bushmaster with a 5.56 mag held 13 rounds, and he dispatched 11 hogs. The semi-auto rifle spits the Black’s 250-grain bullet accurately, and the gun cycled it like a dream.
Not Just for ARs
Don’t get caught believing the 450 Bushmaster was created only for semi-auto, AR-platform lovers. The 450 Bushmaster makes a descent bolt-action gun, too. However, the straight-wall design combined with the bullet fitting entirely inside the case leaves only a thin ledge of brass that circles the mouth, reducing the chance of a feed jam.
Once thought of as a specialty cartridge, the 450 Bushmaster is now a go-to for piles of big-game hunters. As mentioned, it’s a beautiful option for whitetail hunters in kingpin midwest states like Iowa, Indiana, and Ohio that limit rifle hunting opportunities to straight-wall cartridges. Hardwoods are thick in these and other midwest and eastern states with robust whitetail populations, and the landscape is rolling, meaning most deer shots are inside 170 yards.
Another massive nod to the 450 Bushmaster is that .45-caliber bullets are readily available. Rounds can be reloaded for a fraction of the cost of manufactured ammunition if reloaders can secure top-tier propellant and primers. Depending on the bullet type and powder measurement, reloaders can easily create rounds for punching paper and steel on the range, those designed to anchor big game quickly, and self-defense loads that hit like a ton of bricks.
A 450 Bushmaster Believer
Now, for my transformation. It was awesome watching Jeremiah cut down 11 feral hogs in a matter of seconds. The heaviness of his AR-15 and a muzzle break reduced recoil and allowed him to stay in his Leupold glass. With my bolt gun, I may have been able to kill a couple of pigs, but he damn near eliminated an entire sounder of hogs.
Later in the hunt, Jeremiah stocked in on a group of aoudad moving across a cliffy landscape section. Watching through the spotter, I knew the shot was going to be a touch over 200 yards. He was shooting the same Hornady Black ammunition, and I saw the bullet’s impact before I heard the boom.
Aoudad are big, tough critters, and the ram absorbed the shot, but he was quick on the trigger, which is a benefit of those using the 450 Bushmaster in an AR-15, and Jeremiah quickly placed two more shots in the ram’s lungs. He stumbled, rolled, and fell 60 feet to the jagged rocks below.
Today, I own a trio of AR rifles. Two are chambered in predator calibers (.223 and .22-250), but the third is a 450 Bushmaster, and it has been hell on hogs in the Lone Star State.
If you’re looking to bang steel at long ranges and drop big game across mountain valleys, there are better calibers than this. On the flip side of the coin, if you’re looking for a hog, deer, and bear whacker, the 450 Bushmaster is one of the most versatile cartridges out there. If you put your short- to medium-range trust in it, you have a top-end hunting and personal defense caliber that will treat you exceptionally well.