ArmaLite AR-10(T) Match Grade .338 Federal Semi-Auto Rifle


by Jeff Quinn

photography by Jeff Quinn & Boge Quinn

August 14th, 2008




ArmaLite, Inc. of Geneseo, Illinois has been a leader in the development and manufacture of the AR rifle design from the beginning. Since the AR-10 made a spectacular comeback with its reintroduction several years ago, ArmaLite has again established itself as a premier manufacturer of that wonderful rifle, assembling a variety of configurations of the 7.62x51mm (.308 Winchester) to suit the needs of hunters, fighters, and target shooters. Their latest introduction is the AR-10 (T) chambered for the .338 Federal cartridge. While the .308 Winchester is a dandy hunting cartridge, the .338 Federal offers more power for use on large game such as elk, moose, and bear. The .33 caliber cartridges have been popular for use on large game in this country for many years. The legendary Elmer Keith was a fan of the .33 caliber, and had a hand in its development and popularity in the US and Canada. While the .338 Winchester Magnum is the most popular .33 caliber big game rifle in these parts by far, the .338 Federal uses the same bullets, just at a slightly lower velocity. Another way to look at it is that the .338 Federal has as much power as the .338 magnum, but at closer distances. For example, with a 185 grain bullet, the .338 Federal has the same velocity at 150 yards as the .338 Magnum does at 300 yards. Now, when you get into the heavier weight bullets pushing 250 grains and up, the larger case capacity of the Magnum really shines, but the .338 Federal holds its own, and is entirely suitable for medium to large game at reasonable distances. However you want to look at it, the .338 Federal is a very good cartridge, and a welcome addition to the .308 cartridge case family. I really love the .358 Winchester, which shares the same case as the .308 and .338, but with a slightly larger bullet. The .338 Federal splits the difference between these two cartridges, and even though I have a soft spot in my heart for the good old .358, the .338 Federal might just technically be a better cartridge. There are certainly a great variety of .338 caliber bullets available for handloading, and there are already four very good factory loads for the .338 Federal, while factory loads for the .358 are a bit harder to find. Practically speaking, both the .358 Winchester and the new .338 Federal are excellent cartridges; very efficient, and powerful enough to take any game on this side of the world. The .338 Federal has been available in bolt action rifles for a while now, but ArmaLite has just recently started producing semi-auto rifles chambered for the cartridge, and when I learned of this, I had to get my hands on one.

The AR-10(T) reviewed here is very similar to the .308 AR-10(T), but with a larger bore. The two cartridges share the same case, so the two rifles use the same bolt, bolt carrier, and magazines. The .338 rifle shown here ships in a hard case with two ten-round magazines, but can use ArmaLite twenty and twenty-five round magazines as well. The ten-round mags work very well off the bench, and are the ones that I personally prefer.

The .338 AR-10(T) has a heavy twenty-two inch free-floated stainless steel barrel with a target crown. The barrel measures .800 inch ahead of the gas block, which has a section of integral Picatinny rail for mounting a front sight or other accessory. The ventilated aluminum handguard has seven threaded holes along its bottom for mounting accessories and rail sections as well. One of the best features of this ArmaLite rifle is its trigger. It has a two-stage match trigger that releases crisply at barely over four pounds, and is infinitely better than a standard AR trigger for accurate rifle work. The AR-10(T) weighs in at nine and three-quarters pounds with an empty magazine in place, and has an overall length of 41.5 inches. The upper receiver of the AR-10(T) has a case deflector, but no forward assist. Some shooters prefer a forward assist on a rifle, but I do not. If a round will not chamber, I do not want to force it in. I want it out of there. The case deflector is a welcome feature for left-handed shooters like me. The standard A2 style buttstock is comfortable to use, and has a handy storage compartment for essentials. Last year while deer hunting, I was getting mighty hungry, and hadnít brought along my usual can of Spam. I was hunting with an AR-15, and happened to remember that there might be a candy bar in the buttstock, as I tend to use that compartment for such necessities. Sure enough, there was a Snickers bar leftover from the year before. It saved my life, as it had been at least three hours since I had eaten breakfast! Anyway, that buttstock storage compartment can come in handy at times.

Like most AR style rifles, the ArmaLite .338 was very easy to shoot. Recoil is straight back, and not uncomfortable at all. I fired the test rifle for accuracy at 100 yards using the three types of factory ammo that I had available. I tested no handloads, and there is really no need for me to try to develop any. The factory ammunition covers any hunting need, and was very accurate as well. The largest group fired during accuracy testing measured less than one inch. The 200 grain Fusion and the 180 grain Federal Premium load using the Nosler Accubond bullet would both group under one-half inch at 100 yards, and do it all day long. Cold barrel, warm barrel, or hot barrel, it didnít matter. Functioning was perfect during the bench testing and field testing sessions with the weapon. Testing was limited to the 120 rounds that I had on hand. All ammo fed and fired perfectly. Velocities were recorded using my Chrony Master Beta chronograph. I have been using this while my two PACT machines are away, but I am beginning to really like this Chrony. Velocities were recorded at a distance of twelve feet from the muzzle, and are listed in the chart below in feet-per-second (fps). Accuracy is listed in inches or fractions thereof. Bullet weights are listed in grains. Chronograph and accuracy testing was performed at an elevation of approximately 600 feet above sea level, with an air temperature varying between seventy-three and eighty-six degrees Fahrenheit. Accuracy is the average of all groups tested with the same ammo.

Ammunition Velocity Accuracy
Federal Premium Barnes 185 TSX 2695 0.937"
Federal Premium Nosler 180 Accubond 2846 0.437"
Federal 200 Fusion 2648 0.491"

I was delighted with the accuracy displayed by the rifle and ammunition. Even the relatively inexpensive Fusion ammo performed superbly, and this should make an excellent whitetail load. The accuracy was boringly consistent with all three types of ammo tested, and I could predict every time where the bullet would land, as this rifle is just so easy to shoot well. The Leupold Mark 4 scope, with its excellent optical clarity, made the accuracy testing easy on the eyes, as the resolution is near perfect. I attached the scope atop the rifle using my ArmaLite 30mm one-piece base/ring system.

The ArmaLite AR-10(T) is not an inexpensive rifle, but is a good value. It shoots as well as any AR on the market, and better than most, while packing a considerable punch in its .338 Federal chambering. The .338 AR-10 is a very reliable, match-accurate rifle capable of taking large game, while also offering a lot of firepower for more serious purposes. Check out the AR-10(T) online at

For a closer look at the extensive line of Leupold optics, go to

Jeff Quinn





Factory ammo (left to right): 200-grain Fusion, 185-grain Barnes TSX, 180-grain Nosler Accubond.





Leupold Mark 4 scope.



Laserlyte Kryptonyte laser bore sighter saves a lot of ammo.



ArmaLite's AR-10(T) combines power & accuracy - a potent combination.



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ArmaLite AR-10(T) .338 Federal rifle.



The .338 Federal (center) splits the difference between the .308 Winchester (left) and the .358 Winchester (right).







Gas block has integral Picatinny rail for mounting a sight or other accessory.





Handguard has seven attachment points for sling swivels or a bipod.



Flattop upper has integral Picatinny rail and case deflector.



Excellent two-stage trigger.





Bolt & bolt carrier.



Rifle comes with hard case and two ten-round magazines.



Buttstock has a storage compartment for the most essential items.