Bushmaster 5.56mm ACR Semi-Auto Rifle


by Jeff Quinn

photography by Jeff Quinn & Boge Quinn

April 11th, 2010




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Bushmaster Firearms of Windham, Maine is now part of the Freedom Group of companies which includes, Remington, Marlin, H&R, DPMS and a few others. Bushmaster has been in the AR-15 rifle business for many years, and now has a brand new rifle on the market, the Adaptive Combat Rifle, or ACR. According to the press release, Bushmaster, Magpul, and Remington collaborated on this effort to produce a thoroughly modern and combat-ready twenty-first century rifle, and after examining and shooting this ACR, I believe that they have achieved that goal.

Bushmaster introduced the ACR back in January, but production rifles have just began shipping. This rifle that I have here is one of the first twenty-five shipped, and belongs to Tennessee Gun Country in Clarksville, Tennessee. Tennessee Gun Country moves a lot of firearms. They are very well-stocked, have excellent customer service, and very fair prices. I have only been there about three times, but send lots of folks that way. I have never received back a bad report on those folks, so they must be doing things right. Anyway, if you are anywhere near that part of Tennessee or Southern Kentucky, it is worth a bit of a drive to go visit that gun store. Back to the rifle, the folks at Tennessee Gun Country were kind enough to loan it to me for a few days, so that I could play with it enough to write a review. I have been shooting it for only three days now, but so far, I am very impressed with the thought that went into the design of this firearm.

Bushmaster lists this weapon as “multi-caliber”, as they intend to offer various bolts, magazines, and barrels to allow the quick and easy adaptation of the rifle to fire other cartridges besides the 5.56mm. Specifically mentioned is the 6.8mm SPC, but I would like to see the 6.5mm Grendel offered as well. For long range performance, the Grendel is superior to both the 5.56 and 6.8mm cartridges. For now, the ACR fires the 5.56mm NATO and 223 Remington cartridges, and it fires them very well.

The Bushmaster ACR has a well-designed stock, made of a black polymer with textured surfaces where necessary. The ventilated forend has an inner metal heat shield, and the pistol grip has storage for two CR123 batteries. The cheek piece is adjustable for height to work well with a scope or the excellent Magpul folding sights. Every operating control on this rifle is ambidextrous. The charging handle is reversible to either side. The safety lever, magazine release, and bolt release are operable from either side as well. The trigger guard has plenty of room for a gloved finger, and the trigger itself is very much like an AR trigger. The trigger pull on the test gun released with six and one-half pounds of pressure, and feels like a standard AR trigger in use.

The ACR comes supplied with one Magpul thirty-round polymer magazine, which is an excellent unit. The ACR can also use any AR compatible magazine. For bench use, I prefer the twenty-round size, and the ACR worked perfectly with my Vietnam War-era twenty-round Colt magazines. Weighing in at eight and one-half pounds with the sixteen and one-half inch barrel and an empty magazine in place, the ACR has plenty of heft, but is light enough and compact enough for use in tight quarters, if needed. The overall length measures thirty-five and three-eighths inches. The muzzle of the ACR barrel has an A2 style closed-bottomed birdcage flash suppressor attached, and the barrel is machined to accept a grenade launcher, if you have one handy. The gas system on the ACR uses a piston and a two-position gas regulator, to assure reliable function with or without a sound suppressor attached. I did not attach a sound suppressor to this weapon, as it does not belong to me, and I did not want to mar the finish of the flash suppressor, but the barrel is threaded to the standard 1/2x28 thread pattern to accept standard 5.56mm suppressors. The barrel is rifled one turn in nine inches, with a right-hand twist Bushmaster intends to offer the ACR with shorter barrels and in selective fire for law enforcement and military applications, and also with a longer barrel as an option for the rest of us.

The ACR has sixteen and one-half inches of 1913 Picatinny rail atop the receiver, extending out over the barrel about half its length, offering plenty of room to attach a scope mount, the folding sights, and any other needed accessory, such as my 3Bucc brass catcher. For shooting the ACR, Rowdy Yates of Tennessee Gun Country kindly attached his excellent Leupold 1.5 to 4 power Mark AR riflescope, which is a superb choice for a glass on such a rifle as this, offering a wide field of view for close range work, and ample magnification on targets out to several hundred yards. For precise target work to check the accuracy of the ACR, I mounted my 8.5 to 25 power Leupold Mark 4 scope, to see just how accurate this rifle is with a variety of ammunition.

I checked each type of ammo for velocity over one of my chronographs at a distance of twelve feet. During all accuracy and velocity testing, it was a beautiful Tennessee Spring day with sunshine, low humidity, and an air temperature in the seventy-degree Fahrenheit range. Range distance was one hundred yards, with a light wind at an elevation of approximately 541 feet above sea level. Velocity and accuracy results are listed in the chart below. Velocities are listed in feet per second (fps). Bullet weights are listed in grains. Accuracy measurements are listed in inches, center to center of the widest spread of two bullet holes in the group, with the average of all groups for that particular load listed. FMJ is a full metal jacket bullet. HP is a hollowpoint match grade bullet. TSX is a Barnes homogenous copper hollowpoint hunting bullet, hand loaded into Black Hills cases. SS109 is a green-tipped military bullet with a steel-tipped lead core inside a full metal jacket.

Ammunition Bullet Weight Velocity Group Size
Lake City SS109 62 3067 1.5"
Winchester FMJ 55 3012 1.87"
Winchester FMJ 62 2954 0.75"
Black Hills Match HP 69 2800 0.68"
Buffalo Bore Sniper HP 77 2745 0.87"
Handload TSX 62 2931 1.25"
Wolf Gold Match HP 75 2639 1.18"

Three of the loads tested were under one minute of angle, and all turned in respectable accuracy. That 62 grain Winchester load is their cheap white box USA stuff, but it always seems to perform well in most every rifle in which I have tried it. Besides the accuracy testing, I ran quite a bit of the SS109 ammo through the ACR for function testing, as well as some penetration tests on steel plate. At twenty five yards, it handily penetrated two three-sixteenths (.1875) inch mild steel plates, separated by an eight-inch air space. As can be seen in the pictures, the exit holes are much larger than bullet diameter. This stuff performs pretty well in penetration of hard targets, and car bodies and other such barriers are no protection from those bullets. Functioning was absolutely perfect. There were no failures of any kind, and every round fed, fired, and ejected flawlessly.

The Bushmaster ACR seems to be a world-class twenty-first century rifle. I really like the AR-15 family of weapons, but if and when it is replaced as the weapon of choice for the US Military, the ACR would certainly be a worthy successor. While it is still brand new and not battle tested, I believe that it will prove to be reliable under adverse conditions. The ACR offers a lot of versatility, and the barrel and other critical components can be easily replaced in the field, by the soldier or Marine, if necessary. The Bushmaster ACR comes in a hard plastic case, and the rifle is finished in your choice of black or brown. They also offer an enhanced version with folding, telescopic stock and a different flash hider.

Check out the Bushmaster ACR online at www.bushmaster.com.

For a closer look at the excellent Leupold optics shown here, go to www.leupold.com.

For the location of a Bushmaster dealer near you, click on the DEALER FINDER at www.lipseys.com.

To order the ACR online, go to www.galleryofguns.com.

If you are in the market for a weapon, ammo, or accessories, give Tennessee Gun Country a call at 931-552-2118. They will treat you right. They were very kind to loan me this weapon, but I hate to have to give it back!

Jeff Quinn


For a list of dealers where you can buy this gun, go to: To buy this gun online, go to:






Magpul PMAG thirty-round magazine.



Leupold Mark AR scope.



Ammo tested.



Exit holes after penetrating two 3/16" steel plates.



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Click pictures for a larger version.


Bushmaster ACR 5.56mm semi-auto rifle.







Flash hider.





Charging handle.





Two-position gas regulator.





Fold-down sights.



Ambidextrous safety (top), bolt release (center), and magazine release (bottom).





Sling attachment points.





Adjustable cheek piece.



Battery storage in pistol grip.



Barrel is easily removable.