Remember the cute little rabbit named Thumper in Walt Disney’s Bambi? Throughout the entire animated feature, Bambi and Thumper were best of friends. Well, there’s a new Thumper in town—and Bambi would not like him.

The Thumper is what Hornady has nicknamed the new .450 Bushmaster cartridge, intended to be fired in the equally new .450 Bushmaster rifle it is designed for.

New Bushmaster rifle shown with Hornady .450 Bushmaster cartridges and Leupold Mark 4 CQ/T scope. Photo: Hornady


Since it is normally the policy of this magazine to test only firearms and gear that are in full production, I should point out that the test rifle was a preproduction sample and the lower receiver was marked .223-5.56. Other than the receiver markings, and modified magazines, to the best of my knowledge there will be no differences between the test gun and production rifles.

The .450 Bushmaster uses a flattop upper receiver to which a 20-inch barrel is attached. Barrel twist rate is 1:24 and the barrel is marked .450 BFI.

In place of the normal front sight tower is a gas block that has short (1.75-inch) Picatinny rails at the 12, 3 and 9 o’clock positions. Sights are a windage adjustable, fold-down Yankee Hill Machine rear and a fold-down Yankee Hill Machine front sight that is adjustable for elevation. The flash hider/compensator is similar to the “Phantom,” but only has slots at 12, 3 and 9 o’clock with no slot at the bottom.

This hog was put down with the first shot, with the first .450 Bushmaster rifle released, from the first lot of .450 ammunition made by Hornady.

According to Bushmaster’s website, standard 30-round AR-type magazines will be fitted to the rifle, with a capacity of nine rounds. My preproduction sample came with two 20-round size magazines, which held five rounds. A special follower is used and, due to the diameter of the cartridge, feed is straight instead of staggered, as is the case with .223/5.56 rounds.

To me, a rifle without a sling is akin to a handgun without a holster. While there is a standard sling swivel on the A2 size stock, there is no provision for attaching the sling to the front of the rifle. I jerry-rigged an attachment for use on the gas block using an AR buttstock swivel and an old ARMS mount I had lying around.

Rear sight is Yankee Hill Machine folding BUIS.


The overall length of the .450 is the same as the .223 Remington at 2.250 inches. The head of the case has very slight rebate. The length of the case is not a straight wall, but has a barely noticeable taper. This slight taper taper eases extraction, especially as the barrel heats up.

Hornady loads the case with a 250-grain, .452 SST (Super Shock Tip) bullet featuring their new Flex Tip™ technology.

As this is written, the cartridge is so new that ballistic information is not available from Hornady’s website. Using a PACT chronograph with the first screen set eight feet from the muzzle, I obtained an average velocity of 2,211.8 feet-per-second (fps) from a 20-round string. An extreme spread of only nine fps gave testimony to Hornady’s quality control. With this bullet weight and velocity, the trajectory of the .450 Bushmaster cartridge should be just over two inches high at 100, dead on at 150 and about five inches low at 200 yards.

Front sight is YHM folding sight on three-rail gas block.


I had a hog hunt planned with S.W.A.T. Publisher Rich Lucibella and Contributing Writer Ashley Emerson in West Texas a week after the rifle and ammunition arrived. The hunt would give a perfect opportunity to test the new rifle/ammo combo under field conditions.

Knowing that hogs are most active in dim light conditions, I chose to mount a Leupold CQ/T scope on the Bushmaster. This 1-3X scope has 11 illumination settings, uses a fast-to-acquire circle/dot reticle and utilizes a single, readily available AA battery. Another plus is that the CQ/T is rated to last for 600 hours on the medium setting.

I have one slight complaint about the CQ/T. At the forward end of the scope, the area in which the lens cover fits is very short and the cover can be knocked off very easily. The field expedient fix was to tape the cover to the scope’s body.

I zeroed the rifle while sitting at a bench using only my arms and hand for support—the rifle itself was not rested—and obtained 10-shot groups right at 2.25 inches. While this is admittedly not world class, it is most assuredly “minute-of-hog.”

Flash hider/compensator is similar to the “Phantom” but without slot at bottom.

I don’t consider myself recoil sensitive, however, recoil is subjective and what I find manageable others may not or vice versa. Shooting straight on from the bench—a position that naturally sets one up to be pounded—I found the recoil of the .450 Bushmaster roughly equivalent to that of a .308 bolt-action rifle. Shooting offhand from standing or sitting, the felt recoil was much, much less.

The CQ/T scope has a short eye relief that is optimized to work with AR-style weapons—and that normally means the .223/5.56 cartridge. Due to this short eye relief, coupled with the heavier recoil of the .450 Bushmaster, the scope did manage to give me a couple of good whacks on the nose under recoil.

Before I departed for Texas, I had fired 200 of the 300 rounds Hornady had furnished for testing. Functioning of the rifle was 100 percent, giving me confidence that should I corner an angry boar with no way out except over (or through) me, the rifle would perform.

Magazines have special blue follower and are straight feed as opposed to staggered feed as on .223/5.56 AR-type rifles.

The area in which Rich and Ashley’s hunting camp is located had received a lot of rain in the weeks before my arrival, and weeds in some areas were literally over my head. Given the low profile of hogs, the high vegetation, the fact that hogs would not have to depend on their normal watering holes and that I had only four days to hunt, the prospect of finding any hogs was not good.

At mid-morning of the fourth day with time running out, we spotted a young boar that probably weighed around 150 pounds. With the hog on a trot, I tracked him through the scope and fired a single shot and he went down hard. These are tough animals, however, and a second shot was required to put him out of his misery.

Comparison between Hornady .450 Bushmaster and standard .223 cartridges.


Does the .450 Bushmaster have any “tactical” uses? One that comes immediately to mind is shooting through heavy glass that may deflect or disintegrate lesser bullets on impact. Then again, everything does not have to have a tactical use and can be enjoyed simply for what it is. I believe the rifle/cartridge combo will truly shine in the hunting arena.

At this time, with only one game animal having been taken with it, the jury must remain out as to the effectiveness of the .450 Bushmaster. However, putting down a hog with the first round, from the first .450 Bushmaster rifle fielded and from the first lot of Hornady .450 ammunition produced, so far I am very impressed.

A 16-inch carbine version will be available in addition to the 20-inch rifle, and camo versions of each will be available with slight price increases. While the carbine may be a bit handier, I think the full capability of the cartridge would be achieved with the longer 20-inch barrel.

Departing Texas from the Dallas-Forth Worth Airport, the TSA screener asked me to open my gun case so he could view the contents. He asked, “You been huntin’ with a mouse gun?” I took a cartridge from the factory box and said, “No, been huntin’ with this,” and told him about the new rifle and cartridge, to which he replied, “I gotta get me one of rifles.” Good for him—but I think I may buy this one.


Bushmaster Firearms International, LLC.
Dept. S.W.A.T.
P.O. Box 1479
Windham, ME 04062
(800) 998-7928

Hornady Mfg. Co.
Dept. S.W.A.T.
Box 1848
Grand Island, NE 68802-1848
(800) 338-3220

Leupold & Stevens, Inc.
Dept. S.W.A.T.
P.O. Box 688
Beaverton, OR 97075-0688
(503) 526-1400

Yankee Hill Machine Company, Inc.
Dept. S.W.A.T.
20 Ladd Avenue
Florence, MA 01062
(877) 892-6533

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