The Heavy-Barreled AR-15 Varmint / Target Rifle


by Jeff Quinn

photography by Jeff Quinn & Boge Quinn

May 27th, 2003




The AR-15 rifle system has been with us for about forty years now, and has proven itself worldwide as one of the best semiautomatic rifles ever made. After four decades of refinement, the AR system has evolved into a battle-proven rifle that has served most of the free world well in several conflicts as the military M-16.

In its civilian form, the AR system can be divided into two distinct categories.  The first version is represented by the light and handy short-barreled carbines that are very useful for most any serious social situation, such as filling the role of police carbine or defense of the homestead. The second version of the AR-15 rifle system is that of a heavy-barreled, highly accurate, long range rifle for both target shooting and the hunting of small vermin and predators. There is an almost endless variation of in-between styles of the AR-15 that can do double duty as a defensive and precision rifle, but here we will concentrate our focus on the heavy-barreled AR-15s that excel at the accurate placement of bullets on small targets at extended range.

First, lets examine the need for such a rifle. This can be separated  into the needs of the varmint hunter and the precision tactical shooter, such as a police sniper. The varmint hunter has many good weapons from which to choose, including bolt action and single-shot rifles that are capable of fine accuracy. The advantage offered by the AR-15 varmint gun is that of being able to fire repeatedly without moving either the gun or the shooter. With a heavy-barreled AR-15, the shooter can remain in position, moving only his trigger finger to send repeat shots down range. To a groundhog hunter under normal conditions, this means very little, but to a hunter on a prairie dog shoot where you may fire hundreds of rounds per day, this can be important.

A few years back, we had a situation in which groundhogs were destroying our sweet corn crop. The corn was tall and thick, and the groundhogs would leave the safety of their burrows on the creek bank to enter the cornfield and steal a few ears at a time. They had to cross a five-foot clearing to get to the corn, and they crossed this at full speed. Any shot that could be taken had to be made in that five-foot clearing, at a running target. The area around the field was heavily wooded, but there was an old combine at one end that offered a good view of the groundhogs escape route.  The groundhogs would enter the field, grab the corn, and then exit to the safety of their home. I would watch from the top of the old combine, and when a corn stalk was pushed over, it would only be a few seconds until the fat little pigs would head across the clearing. Any shooting had to be quick and accurate, or the groundhog was home free. Sometimes, as many as three pigs would cross the clearing together, each with an ear of corn in his mouth. Sure, a single-shot or bolt action rifle would have let me harvest one of the little corn thieves,  but getting the second or third was out of the question. This type of hunting situation  is where an accurate semi-automatic really shines, and none is better than an accurate AR-15 with a good scope sight. The heavy barrel helps to steady the gun for repeat shots, and the extra length of the barrel adds velocity for greater terminal effect. I did not get every groundhog that crossed that clearing, but more than once I was able to connect on multiple targets, getting as many as three at a time. After shooting began, the pigs wouldnt be back that day, but would live to steal more corn the next day. Without the ability to pop more than one at a time, the corn harvest would have been greatly reduced that year.  As much as I like a good bolt action .22-250, the AR-15 was the perfect rifle for this situation.

Another situation in which the heavy-barreled AR-15 excels is in the role of a police sniper weapon. There are instances in which a skilled police marksman must make critical precision shots at a hostile target. The target is often moving around, and if a second or third shot is needed, it is needed immediately. The AR-15 allows almost instantaneous repeat  shots, without taking the sight off of the target. With modern .223 ammunition using heavy bullets, the AR-15 has ample power and penetration to get the job done, with relatively low recoil.

For this article, we gathered a sampling of some of the best heavy-barreled AR-15 type rifles on the market. This is by no means meant to be a complete representation of every heavy AR available, but these are each well-built and accurate weapons.  The guns represented here are from Bushmaster, ArmaLite, Doublestar, Rock River Arms, and DPMS. Each rifle is of the flat top configuration to easily facilitate the mounting of a precision scope sight.  All of the test guns were fitted with a heavy twenty-four inch barrel that thankfully had no muzzle appendages of any kind. To make an accurate AR-15 takes a good barrel. To make an AR-15 that will hold its accuracy repeatedly shot after shot, it takes a heavy barrel. Each of these rifles wore a barrel that measured around an inch rear of the gas block, with the diameter of the barrels forward of the gas block as follows:

Rifle Barrel Diameter
ArmaLite M-15A4(T) 0.798"
Bushmaster Varminter  0.740"
Doublestar   0.924"
DPMS Panther  0.922"
Rock River Varmint  0.924"

The Bushmaster, Doublestar, and DPMS barrels were fluted to reduce weight and promote faster cooling.

Each of these rifles has a stainless barrel, with the exception of the Bushmaster, which has a chrome-moly barrel. The pistol grips of the ArmaLite and Doublestar are of the standard hard plastic AR-15 type, while a rubber finger grooved pistol grip is featured on the Rock River and Bushmaster, and a target type pistol grip with "Olympic style" hand rest is included on the DPMS. Trigger pulls were measured with a Lyman digital trigger pull gauge, and are as listed here:

Rifle Trigger Pull
ArmaLite M-15A4(T) 4.5 pounds
Bushmaster Varminter  4.4 pounds
Doublestar   7.1 pounds
DPMS Panther  6.5 pounds
Rock River Varmint  3.5 pounds

Each of these rifles weigh in the eight and three-quarters to ten pound range, providing a very stable yet still portable shooting machine. During the test firing of these guns, each of them fed, fired, and ejected every round without a hitch, using a variety of ammunition, both factory and handloads. Two really great performing loads in each of these guns were factory loads from Winchester. Their 55 grain Ballistic Silvertip premium ammunition performed superbly, as expected, but also the 62 grain USA full metal jacket ammo grouped very well, in some cases beating out the Silvertip. Each of the rifles tested had fast twist rates to handle the heavier bullets well. With every load tested in these rifles, all groups measured less than one inch, with most measuring half of that. This was while shooting at a range of 110 yards with a moderate gusty wind. I believe that each of these rifles are capable of very fine accuracy with the loads that suit it best. Half inch groups with factory ammo is very good, and each rifle tested did that or better with the Winchester Ballistic Silvertips.

Shooting with each of these fine firearms was a pleasure. The AR-15 rifle system has proven itself in recent years to be an excellent platform for a varmint and target rifle. With practice and a good scope sight, accurate hits at several hundred yards are easy. The recoil is light, and the ergonomics of the AR system is almost perfect. The heavy barrels on these guns are free-floated for consistent accuracy.  The flat top receivers are perfect for mounting a precision scope. I like to keep a heavy and a light AR around, but if I had to choose only one, I would keep a heavy.  They are easier to shoot well at long range, have less muzzle blast, and greater velocity than a short barrel. For a fast shooting varmint gun, they cant be beat. For a police sniper rifle, the heavy AR is almost perfect. Where legal, they make a good deer rifle with the proper ammo in skilled hands.  Follow-up shots on a running coyote are easier with a heavy AR than any other type of rifle.

You can check out the complete specifications on each of these fine rifles at the following websites.

Bushmaster Varminter:



Rock River Arms:


Choosing any one of these rifles would be a winner. Look at the websites, compare prices, and check the specifications that best suit your needs. I recommend any one of the rifles tested here, and regret having to send them back.

Jeff Quinn

[Ed. Note: For further reading, check out these articles by Jeff Quinn:

Customized Bushmaster XM-15

Bushmaster Varminter

-Boge Quinn]

Got something to say about this article? Want to agree (or disagree) with it? Click the following link to go to the GUNBlast Feedback Page.


Click pictures for a larger version.


Heavy-barreled AR-15s tested (top to bottom): Doublestar, Bushmaster Varminter, Rock River Varmint, ArmaLite M-15A4(T), DPMS Panther.



All the guns tested for this article featured heavy stainless steel barrels, with the exception of the Bushmaster Varminter's chrome-moly barrel. Left to right: Doublestar, Bushmaster Varminter, Rock River Varmint, ArmaLite M-15A4(T), DPMS Panther.



Jeff tested trigger pull weights on all the rifles with a Lyman digital trigger pull gauge.



ArmaLite's M-15A4(T) features a standard hard plastic AR-15 style pistol grip, round composite hand guard, unfluted stainless steel barrel, and an accessory rail on top of the gas block.



The Bushmaster Varminter features a rubber finger-grooved pistol grip, ventilated checkered aluminum hand guard, and a fluted chrome-moly barrel.



The Doublestar rifle features a standard hard plastic AR-15 style pistol grip, checkered ventilated aluminum hand guard, fluted stainless steel barrel, and an accessory rail on top of the gas block.



The DPMS Panther features a surprisingly comfortable "Olympic style" adjustable pistol grip, adjustable butt plate, and fluted stainless steel barrel.



The Rock River Varmint rifle features a rubber finger-grooved pistol grip, checkered aluminum hand guard, unfluted stainless steel barrel, and a "skeletonized" accessory rail on top of the gas block.

Both the Author and the Webmaster were very impressed with all the rifles rested. Boge freely admits he can't shoot with the likes of Jeff, but a quality rifle and scope, coupled with a good shooting rest such as the Target Shooting Inc. Rifle Rest, even makes Boge shoot well!



All rifles were tested with a Pentax Lightseeker 6-24X variable scope. The Lightseeker is a very impressive scope, featuring a 30mm tube and target-style adjustment turrets. Parallax adjustments were perfect, the variable-power adjustments were precise and repeatable, and the scope offered a very clear and bright picture. A quality scope such as this is essential for accurate shooting, and the excellent array of rifles tested deserve the best!



All guns tested shot extremely well with all ammunition types tested, but Winchester's .223 ammunition stood out from the crowd. All the rifles tested preferred the Winchester offerings above all other factory brands. Winchester's "USA" budget FMJ ammo even proved the equal of their premium Ballistic Silvertip ammo in some of the rifles!






Send mail to with questions or comments about this web site.
All Content Copyright 2000-2008
Last modified: February 19, 2008

Web design by: Boge Quinn