The wildly popular AR15 platform is spurring modifications on over-the-counter guns that heretofore were the province of do-it-yourselfers who had a Brownells catalog and a credit card handy. Two modifications of the original design found on more and more ARs are the “tactical” forend, consisting of a four-sided Picatinny rail and flip-up sights that can be raised into position when needed. The tactical forend is especially useful when applied to a flat-topped receiver topped with a matching Picatinny rail. The forend rail can receive any type of laser or illuminating device that carries a clamp. These features were developed to answer the needs of military and law enforcement and action-riflecompetitors.
The AR15 platform lends itself to fulfilling the needs of the user like no other design, which made our task of assembling four different carbines both a challenge and a pleasure. They are the $1554 Smith & Wesson M&P 15T No. 811001, the $1054 DPMS RFA2-AP4A Patrol Carbine, the $1150 left-side-ejection Stag Arms 15L Model 2TL Pre-ban, and a Bushmaster Patrolmans Carbine No. BCWA3F 16M4, which comes with options that bring the total suggested retail price to $1534. Each of these compact ARs offer the tactical forend and flip-up sights mentioned above and a flash hider, adjustable-length stock, and single-stage trigger. Also, the DPMS Patrol Carbine, the Stag Arms 15L, and the Bushmaster came with A2-style front sights that were adjustable for elevation. The S&W gun lacked that feature.
All four were chambered for .223 Remington or 5.56mm rounds. For test ammunitions, we chose two premium rounds and the highest quality, most economical remanufactured ammunition we could find. The premium rounds were 62-grain Hornady TAP and 62-grain Federal American Eagle FMJ ammunition. To perform the bulk of the work, such as zeroing our scopes and performing rapid-fire drills that ate up hundreds of rounds, we chose 55-grain full-metal-jacket rounds from Georgia Arms http://www.georgia-arms.com/.
Our test procedure was arduous. To collect accuracy data we fired five-shot groups from the 50-yard benches at American Shooting Centers in Houston http://www.amshootcenters.com/. Each gun was tested with the supplied open sights and with a Millet DMS-1 variable power scope set at 4X magnification. Mounting the scope with Zeiss rings upon a one-piece riser from Yankee Hill Machine (part number YHM-227A, $33 from yankeehillmachine.com) made the transfer from gun to gun simple.
We chose Milletts new 30mm 1-4X scope because it offered flexibility of magnification and also a reticle that we felt was suitable for tactical as well as longer distance applications. The reticle featured a horizontal crosshair that stopped short of the circle that designated its center. The vertical line reached only from the six oclock border of the lens to just below the circle. We liked this reticle because the open field in the top half of the lens offered a less cluttered view for the operator. In addition points such as the bottom of the circle helped us visualize quick hold over positions for additional elevation. Inside the circle was a small black 1-MOA dot and the circle itself was backed by orange-colored illumination. The intensity of the illumination was controlled by an eleven-point dial found on the left side of the scope directly opposite the windage control.
When shooting groups we were actually able to center the dot on the 0.75-inch wide diamond found at the center of our Birchwood-Casey three-inch target spots. For speed shooting we simply used
the black ring. We would have preferred that the orange illuminated ring was visible in daylight. That would have made target acquisition much faster. Hidden behind the black ring, the orange was only visible in lower light conditions. This was helpful for tactical entry, but the Gun Tests action rifle team was a little disappointed.
For speed shooting and fast-action handling tests, we moved to Phil Oxleys Impact Zone in Monaville, Texas (theimpactzone.us). First, we recorded elapsed time from the draw. Start position was low ready with the muzzle about 45 degrees with the ground and the safety on, with buttstock pivoting on the shooters pectoral muscle. The stock was adjusted to the first position short of full-length. Target distance was 12 feet. This drill was performed ten times.
For our rapid-fire test we added two more targets spaced 4 yards apart. In this drill the supplied open sights were used, and the trigger was shown no mercy. We hammered the IDPA-style cardboard silhouettes (measuring 30 inches high by 18 inches across) with one shot on each target, then two shots on each target; two shots to the body one to the head, four shots on each target, etc. Each gun was left smoking. Here is what we learned.
Stag Arms
Model 15L 2TL .223, $1150
With so many common features shared by our four carbines, the Stag 15L 2TL stood out by offering the left-handed shooter left-side ejection and ambidextrous thumb safeties. A right-side magazine release button was in place, but it could be activated from the left side thanks to a lever that when pressed pulled inward on the release. We found it was much harder to work this lever than applying direct pressure to the right-side button, but it got the job done. The left-side thumb safety was also left in place with a right-side safety lever attached with an Allen screw tapped into the shaft.
We spent a lot of time shooting this carbine from both the right and left shoulder, both standing and from the bench. Left-side ejection did not seem to be much of an issue in either case as the case deflector directed the spent shells forward at about a 10 oclock angle. We found that the opposite side of the ambidextrous safeties was in the way of the trigger finger at times. Full-time left handed shooters might consider changing to a right-side only lever. But in all fairness we have not found any ARs (or similar rifles) that have managed to position the ambidextrous safety levers so that the weak-side lever is completely out of the way.
There were two sling loops on the Stag Arms carbine. One was attached beneath the front sight and the other was clamped to the barrel within the confines of the front sight assembly. The choice of loops can make the carbine easier to carry, but when shooting,
slinging up with either loop could have a negative effect on accuracy. We should point out that the rail forends on all four carbines were free floating, meaning that nothing touches the barrel from the barrel nut forward. This prevents any possibility of barrel deflection or accuracy degradation due to pressure from the support hand, the weight of mounted accessories, or the pull of a sling. Barrel deflection due to sling pressure can be avoided by mounting a sling swivel directly onto the forend rail by using a rail sling adapter such as those made by Midwest Industries. Four different models were listed in the Brownells catalog with the option of clamping on a loop or a swivel stud that could also be used to attach a bipod. The Stag Arms carbine was fit with a Samson Manufacturing forend. The forend was fully ventilated with a 7-inch-long Picatinny rail and three holes drilled and tapped for stronger mounting options. Every other slot was numbered and lettered to coordinate mounting, (“T” for top, “B” for bottom, “R for right and “L” for left). The pistol grip was hard plastic with one finger groove. But the top forend rail was visibly out of line with the rail that stretched across the top of the receiver.
The front sight of the Stag was adjustable for elevation in typical A2 fashion by depressing the detent and turning the post clockwise for a higher point of impact or counter clockwise to bring the shots down. The flip-up rear sight was adjustable for windage only and could be used full time or stowed in favor of an optical scope. The unit was seated by a cross pin that offered a clamp on the left side (engraved with a forward arrow for proper mounting) and a nut machined for a slotted screwdriver. When the nut was removed, it stayed with the unit thanks to being attached by a wire. The unit was held in its down position by a heavily sprung lever. The unit was also held in its up position by a heavy spring. So, we had to press down on the unit and pull back the catch lever to bring it upright. Replacing the sight to its down position also required two hands, which was a characteristic we did not prefer.
Once the sight was upright, there were three apertures available to the shooter. The first visible aperture was the small peep sight that we used for our bench session. That aperture could be peeled back to reveal a larger one. Atop both apertures was a matching notch. This was a coarse setting that could be used in very close quarters. The unit was rather tall and offered one other option. We thought the design of the Stag rear sight unit would prove especially useful in co-witnessing due to its height and the versatility it offered in terms of notches and apertures. Co-witnessing means both the iron sights and the scope reticle are tuned to the same point of impact. The advantage is the ability to use either the optical sight or the iron sights by changing almost nothing other than your attention. The redundancy of the sight picture also provides backup should one source fail.
We began our live fire tests from the 50-yard bench supported by a Caldwell Tack Driver bag that was filled with heavy media and long enough to support the entire forend. Each shot was fired with a careful controlled press that brought to light the major shortcomings of the Stag Arms carbine. Using the smallest aperture, we settled in with a hard focus, took up the trigger, brought our breathing to a stop and tried to time our press between heartbeats. Sometimes a shot broke and sometimes the trigger simply halted at a false second stage. This level of trigger creep made group shooting extremely tiring. That is why the extreme spread in the group sizes we recorded was so wide in comparison to our other test guns.
We also found that the windage adjustment offered by the rear sight was too coarse and in our view only marginally effective. With the Millett DMS-1 scope, we were able to shoot tighter groups. But the scope did not help us work the trigger.
Our first action test demanded that the shooter bring the carbine up onto a near target, release the safety, and fire a shot at the first acceptable sight picture. It was during this portion of our tests that we realized that the ambidextrous safety was in the way just enough to force a change of grip for some of our staff. The Stag came with slip-on rail covers making for a more comfortable support grip. In professional use many operators wear gloves, but we dont think the tactical rail forends were necessarily uncomfortable to the bare hand. Nevertheless, the rail covers can be cut to size to cover any length of rail.
The results of our single-shot drill produced an average elapsed time of 0.79 seconds from an audible start signal for a center-mass hit. Our next action test found us hammering the targets, emptying one 30-round magazine after another. The sights were adequate for this type of assault, but we found that the open notch machined into the top rim of the apertures was actually of limited use. With the front sight in focus, the notch was a blur, making its acquisition undependable especially in dim light.
One aspect of the adjustable-length stock is that it can help compensate focal length for a variety of eye strengths. Of course, using a scope is the great equalizer for old eyes. We also felt that the grip was uncomfortable. The finger groove rarely seemed to be in the right place, and no matter if we fired right handed or left handed, the safety lever on the weak side of the receiver seemed to be in the way.
We had one failure to feed during our test of the Stag Arms carbine wherein the offending round was left with the case rim peeled back.
DPMS RFA2-AP4A
Patrol Carbine .223, $1054
The DPMS carbine that we obtained was very similar to the Stag Arms model except it operated with right-side ejection and left-side-only thumb safety configuration, as shared by our remaining three test guns. The four-sided rail on the free-floating tactical forend was devoid of markings. The rail atop the receiver and the forend rail were divided by the Delta ring. In all, this carbine was not as eye catching, but we could plainly see that this was a well put together machine.
There were numerous models to choose from on the DPMS website, but each gun can be a variation of the listed models. For example, our carbine was very close to a model that goes by the name “The Agency,” listed under the heading of LE firearms. Shared features included the Ergo Sure Grip and the Mangonel flip-up rear sight. But our model did not include an EoTech scope or a two-stage trigger. Two 30-round mags (one more than the other carbines afforded) plus a nylon web sling and a tool kit were included.
We liked the rubber Ergo Sure Grip much more than the hard plastic grips found on the Stag Arms or Smith & Wesson models. It had a gentle palm swell, shallow finger grooves, a tacky grip surface and a web guard that acted as a beavertail shielding the rear edge of the receiver from the web of the hand. The Ergo Sure Grip was hollow with room for storage of a small tool or scope batteries. But the cap kept coming loose, and before long we were ready to glue the cap shut.
The Mangonel rear sight was bolted on to the Picatinny rail with a sturdy 13mm hex nut. This was not a piece you would take off and put on casually. It was meant to stay in place and work in close quarters, co-witness with a scope, or go into action quickly in the event of a scope failure. The aperture size was 0.150 inch, which is comparable to the larger of the two peep sights found on most A2 rear assemblies. Bringing the spring-loaded aperture bar into action simply meant lifting it into place. This was a quick one-finger operation even while wearing gloves. Lowering it was a two-fingered operation. Lift the sight, push the support bar forward, and the aperture snapped downward out of the way. Windage was adjustable by turning the knurled A2-style knob.
From the 50-yard bench we felt that the large aperture of the Mangonel sight put the DPMS carbine at a disadvantage. Our overall average group size was about 2.5 inches, but we could chalk that up to not having the smaller peep sight at our disposal. With the Millett DMS-1 scope in place, we were able to get a very precise sight picture.
Our DPMS carbine favored both the 55-grain FMJ Georgia Arms ammunition and the 62-grain Hornady TAP rounds. Five-shot groups firing each of these rounds ranged in measurement from 0.8 to 1.2 inches across. We feel we could have done better except for interference from a mild creep in the trigger that was unpredictable. One other distraction was the adjustable stock. Sometimes the detent pin did not want to find its seat. Turning down the screw at the center of the detent pin put an end to this problem.
Whereas the DPMS carbine suffered through the longer range shooting with the large-aperture Mangonel sight in place, the simple sight picture helped us find the targets quickly at close range. Our elapsed time from low ready with safety on to a center-mass hit dropped below 0.70 seconds as we neared our tenth repetition of the drill. Average elapsed time was 0.72 seconds. The DPMS offered the shooter a solid, positive feel when engaging multiple targets as fast as we could pull the trigger. The gun felt light, easy to steer, and eager to shoot. There were no malfunctions of any kind throughout our tests.
Bushmaster Patrolmans Carbine
No. BCWA3F 16M4 .223, $1534
Our Bushmaster Patrolmans Carbine was yet another interpretation of the flat-top AR. The base price of this model was $1230 including the Fiberite Six Position adjustable stock and A2 front sight. But we picked several options to bring it into spec with our other carbines. A 4 Rail Free-Floater Forend (YHM-9479) was in place plus an Ergo Sure Grip (ARG- KIT). With another Ergo Sure Grip clamped to the bottom forend rail (ARG-FWD), we thought we were seeing double.
The forend grip could be placed anywhere along the bottom rail as long as it was far enough forward to clear the magazine. A large knob with a coin or screwdriver slot and knurled edges held the grip in place. With two pistol style grips in place, our stance took on a narrower profile. This would be especially advantageous when traveling down a hallway or taking cover in a tight space. The forend itself appeared to be fatter. This was because the rails were covered with slip-on Sure Grip rail covers featuring the Bushmaster logo, (SCH-6L). The rail covers created a smooth, rounded feel to the forend and increased its overall width by about 0.3 inches.
Another “optical illusion” was the A3-type removable carry handle, masking the true design of the receiver. The handle contained an A2 dual aperture rear sight with 1/2 minute of angle adjustment for both windage and elevation. There was also a hole in the carry handle for mounting a top rail. The carry handle/rear sight unit was held in place by two heavy knobs. This unit did not offer the same quick-change option afforded by the flip-up sights, but this unit was easy to take off and reapply. What it did offer was a very accurate sight picture. We also found that as long as the shooter maintained the original sight radius and returned the unit to the same position, taking it on and off had little or no effect on its zero.
The A2-style carry handle was standard equipment on this model, but there are at least three different flip-up rear sights to choose from on the http://www.bushmaster.com/ website. The muzzle was capped with another option, the Izzy Flash Suppressor/Compensator (IZ-102660). We wanted to find out if the Izzy would provide greater recoil control than the classic “birdcage” flash hider.
Seated at the shooting bench and performing a controlled press brought out the true nature of the trigger. There was no creep or grit at any point in the sweep of the Bushmasters trigger. The carry handle rear sight unit may not have offered the versatility of the flip-up sights, but there was far less compromise in attaining a fine sight picture. Shooting with the iron sights the Bushmaster favored the 62-grain rounds with groups averaging less than 1.5 inches across. With the Millett DMS-1 scope in place groups were measured in the one-inch range firing the heavier rounds. Shooting the Georgia Arms 55-grain FMJ rounds produced the best groups in the test varying in size from approximately 0.6 to 0.8 inches across.
Our rapid-fire tests taught us more about the capability of the carry handle sights. In our one-shot “draw and fire” drill, our elapsed time lagged behind the other carbines by about 0.15 seconds. Finding the aperture inside the carry handle was simply slower, but the hits were more accurate. Without making excuses for the setup of our Bushmaster, a close quarter battle can sometimes require the same type of precision needed on a more distant target. Especially in a situation where only a small target area such as an adversarys exposed elbow or eye socket is available.
In our multiple targets rapid-fire drill, the refined trigger of the Bushmaster helped us land better hits, especially on head shots. The vertical grip did not necessarily make this drill any faster. But shooters who typically hold an AR by the front of the magazine well rather than the forend preferred the vertical grip in place. We felt that the Izzy compensator helped put us back on target quicker, but just how much was too difficult to quantify. The Izzy was not a full-blown compensator, but we noticed that our Bushmaster jumped less. With the versatility of the A3 design, the operator can have any sight picture or system they want on top of the receiver. Beneath its rail the Bushmaster XM A3 offered an excellent trigger and reliability.
Smith & Wesson M&P 15T
No. 811001, $1554
This was our first chance to test of any of the Smith & Wesson ARs. We found the M&P 15T to be the most visually striking of our test guns. What distinguished our 15T from the others was the longer rail forend, the deletion of the A2 front sight that left the forend open at the front, and the application of flip-up sights front and rear. The forend on our other guns measured about 7 inches long, but the one applied here reached a full 10 inches with about nine of those inches filled with usable slots in the Picatinny rail. This forend was similar to the Samson Manufacturing unit found on the Stag Arms carbine but was more ornate. The vents were oval shaped and beveled. Horizontal lines were machined into the recessed portion of the rail. The extra machining enhanced the carbine visually and increased surface area to hasten cooling. There were small ports leading from the inner crook of the rail upward to channel air past the barrel and cool the rails themselves. Each rail featured five holes drilled and tapped for additional mounting options, such as locking down a given component. The rail was so pretty (with full graphics marking every other notch) that we hated to cover them with the supplied Sure Grip rail covers. Otherwise, the M&P 15T was (save for some very nice graphics) a standard AR. The grip was hollow plastic with one finger groove, but we did think the action of the adjustable stock was smoother and tighter than most.
We judged the sights both front and rear to be among the best of the flip-up units we have seen. Smith & Wesson refers to them as Battle Sights. To put them into position required simply lifting them up. Lowering them required only that the operator press in the button found on the left side of each unit. The front sight was elevation adjustable by rotation, but this required a supplied wrench. We could see how a pliers or other tool could be used, but that would certainly mar the post to some degree. The rear unit offered two apertures of typical A2 dimensions that rotated in and out of position. To fold the rear sight down, the larger of the two apertures must be in place. Windage adjustment was on the right side controlled by a dial that held its adjustment securely with a ball detent.
At the 50-yard bench accuracy was remarkably consistent. Using the open sights, we found the M&P 15T was capable of shooting groups that averaged about 1.3 inches across with each of our test rounds. Mounting our scope reduced group size to about 1.0 inches or better for all shots fired. But we did experience some difficulty.
To begin with, the trigger feel of the Smith & Wesson M&P 15T differed from our other carbines even though trigger resistance on all four carbines measured out to about 7.5 to 8.0 pounds. The M&P featured little or no takeup and a glass-hard break. We liked this. But by the time we had started shooting groups with our second test round, we noticed that creep and stall had entered the trigger. Upon inspection we found that the lower pin that secured the trigger in the receiver was working its way out from the left side. This accounted for the drag in the trigger. We pushed the pin back into place and discounted the affected group. This problem did not reoccur.
But we also felt that the bolt was not cycling freely. It felt sluggish, most noticeably with the Hornady TAP ammunition. Perhaps this contributed to two stoppages wherein the nose of the Hornady bullet smashed against the feed ramp rather than enter the chamber. Checking our chronograph, all of our rounds were producing a healthy dose of consistent velocity, so the power of the ammunition was not the problem. We inspected and re-lubricated the bolt. At the bench we did not use the supplied 30-round Smith & Wesson magazine because it was too long and impacted the bench when the gun was settled into the rest. A shorter military issue 20-round magazine was used for all our benchrest shots. The follower appeared to be very dirty, so we changed magazines. We experienced no further stoppages, but we still felt that the M&P was not cycling as freely as the other carbines even with the supplied Smith & Wesson magazine.
In our test of raising the gun on target, flicking off the safety and delivering a single shot, the M&P 15T was the hands-down winner. Our operator complained that the safety was too tight and difficult to turn off and on, and that resulted in one run taking 1.16 seconds to complete. But the elapsed time for every other run ranged from 0.56 seconds to 0.70 seconds. In our multiple targets rapid-fire test, the sights continued to help us balance speed and accuracy. But our staff reported that of our four test guns, the Smith & Wesson seemed to recoil the most. The M&P weighed about 6 ounces less than its competitors, and the barrel was fit with a bird cage style flash hider rather than a more effective compensator. But we felt that the recoil was mostly related to the choppy action of the bolt. This could be the result of any number of parts suffering undue friction or even a constriction somewhere along the gas flow.
DEFENSE_RIFLES_ACCURACY_1007.pdf
STAG_ARMS_15l_DEFENSE_1007.pdf
DPMS_RFA2_PATROL_DEFENSE_1007.pdf
BUSHMASTER_DEFENSE_CARBINE-1007.pdf
