The last five years have been a roller-coaster ride for the gun industry, with an emphasis on AR-style rifles, which at one point were sold out nearly everywhere and were often selling above MSRP when you could find them. Now, AR sales are mostly down, except for a segment of the market that seems steadily abuzz, the larger caliber ARs, most commonly the 308 Winchester chambering. Most of the larger population of AR-15 owners can’t be sold on the larger chambering simply because of heavier rifle weights, but steadily emerging, is a group of gun enthusiasts who seem not to be deterred by the extra weight. This is evident by the many 308-caliber AR-style guns on the market today made by many gun manufacturers, including Patriot Ordnance Factory and DPMS. These firms are not newcomers to this market; DPMS, in fact, was one of the first companies to develop and manufacture a line of 308 Win. AR rifles about 15 years ago.
We approached this test as if we were already gun owners, and we were considering whether to add a .308 semi-auto to our existing collection to add range above and beyond what our 5.56/.223 semi-autos could develop. So we chose two slightly different configurations to see what seemed like the better mix of weight, handling, and recoil. One of our test guns was a DPMS LR-308-AP4, which has an MSRP of $1269 in its base configuration (with an aluminum free-float handguard), and a suggested retail price of $1399 with an optional free-float quad-rail, as tested here. It is a 16-inch-barrel carbine with a direct-gas-impingement operating system. We pitted it against a Patriot Ordnance Factory Gen3 P308-20 BLK with an MSRP of $2599. This 20-inch-barrel rifle uses a 3-position short-stroke gas piston system to operate the action (your choice of normal, suppressed, and bolt-action operating modes).
We used a three-person test group for this evaluation, all proficient shooters in their area of interest. One was a longtime AR-15 5.56 rifle shooter and collector. The second team member prefers large-caliber bolt-action rifles, and the final member mainly shoots 22 rimfire rifles and pistols. Would trigger time behind either of these 308-caliber AR-style rifles convince them to part with a lot of money to buy one?
First, our testers weighed in with their initial takes on each gun’s fit and feel, owner’s manual, teardown process, controls layout and execution, and field prep. During administrative handling with triple-checked empty guns (and no ammunition whatsoever in the room), all were impressed with the guns’ heft and balance. The DPMS LR-308 A4 carbine had the tighter fit, we thought, and really felt familiar. They both had up-to-date features, such as M1913 Picatinny flat-top uppers, ambidextrous mag releases, MagPul furniture, ambidextrous selector switches, and proprietary free-floating quad rails. Both guns came with 1:10-inch twist rates in their barrels, capable of handling a range of bullet weights from 147 to 185 grains. Both guns had a great cosmetic finish and didn’t rattle.
The manuals were well written and easy to follow. We consulted them in the next phase of this evaluation, which focused on the major systems and internal parts, including disassembly and cleaning, which makes our guns ready for range testing.
DPMS LR-308-AP4 Details
The DPMS LR-308-AP4 16-inch carbine was equipped with an upgraded Panther flash hider, whose tips were distinct and sharp for puncturing glass and other light barriers. The barrel had the distinct M4 barrel contour, topped with an older A1-style front sight post/gas valve, which is pinned to the barrel. It appeared to be correctly installed and was secure. The DPMS came with a factory-installed free-float quad rail, which was also well attached, and our team noted that everything was tight and lined up correctly with the upper receiver. Atop the M1913 rail sat a detachable A3-style carry handle with A2-style rear sight. This item appeared well made and held out the promise of good shooting accuracy. We found the A3 carry handle/A2 rear sight assembly clamped directly to the upper receiver’s flat-top M1913 Picatinny rail. Removal was easy, requiring two knobs be loosened. The assembly lifted right off the rail.
The buttstock again was familiar; DPMS uses a standard AR-15 6-position carbine stock. It functioned properly and had a considerable rage of adjustment. However, if this were our gun, the team agreed that upgrading the stock would be a vast improvement over the original.
The DPMS test gun came equipped with an upgraded Ergo pistol grip and an upgraded ambidextrous selector switch. In our view, the grip was a definite improvement over the stock A2 pistol grip, in part because the Ergo grip also came with a compartment, which had its own cover/plug. The upgraded ambidextrous selector switch uses a hex-style screw to attach the secondary switch. On arrival, this was loose and had to be tightened. This option produced mixed opinions among the testers. The AR shooter was opposed to redundant controls, while the other two testers liked all the bells and whistles.
During disassembly, we found the rear takedown pin to be very tight; none of the three testers were able to budge the rear takedown pin by hand. As suggested in the manual, we used a punch and small hammer to manipulate the rear takedown pin. A closer examination of the rear takedown pin revealed that the difficulty was caused by the head of the takedown pin being lodged tightly against a profile milling that intersects with the pin’s seating area. If left alone, a small hammer would be required to seat the pin and a punch would be required for removal, so field-stripping the gun would not be easy. The team chose to resolve the issue rather than send the gun back to DPMS for warranty adjustments. The receiver was secured in a vise with the takedown pin fully extended. A Dremel tool equipped with a 1.5-inch cutting/grinding wheel was used to carefully grind the top edge of the takedown pin, grinding in a relief that allowed the pin to fully seat unobstructed. The white metal was twice treated with Brownells Dicropan Cold Blue, then lubricated. The modification was successful; the rear take-down pin worked as predicted and looked good.
The front takedown pin was easily manipulated by hand, allowing the upper and lower receiver to be separated. Once inside, we found the bolt carrier group and charging handle were simple to remove, with disassembly and breakdown identical to a 5.56-chambered AR-15. The barreled upper receiver was cleaned and lubricated using patches, chamber brush, and AR-15 cleaning brush. The critical areas seemed easier to clean than on an AR-15 due to the enlarged dimensions of the upper receiver and barrel extension. DPMS designed its milled billet lower receiver from the ground up, and although the receiver is 30% larger than a standard AR-15, the rear fire-control pocket was milled to dimensions that would utilize existing AR-15 lower parts. Aside from the oversized mag well, the lower functioned and looked identical to an AR-15 lower assembly.
Using a gauge on the empty rifle, we saw the trigger had a consistent 6.4-pound trigger pull and felt like a typical single-stage combat trigger. The selector switch spring felt light, but the switch moved unobstructed and did lock into place crisply. The mag release was a single control, as was the larger bolt-release control.
Overall, the DPMS lower receiver and parts scored well by all three testers, however, since modifications with a grinder were performed, we deducted some points.
Patriot Ordnance Factory Gen3 P308-20 BLK Details
The POF USA Gen3 P308-20 was 42 inches long with a 20-inch fluted barrel tipped with a custom triple-port muzzle brake. On top was a sleek monolithic rail stretching 14 inches in length. A MagPul PRS adjustable buttstock met the shooter’s shoulder. The team agreed the rifle felt strong and hefty, and they were pleased with the overall feel. It was well balanced, the metal finishes and coatings were uniform and looked very nice. The mill work on the billet upper and lower receiver was well done.
The receivers fit tightly together and didn’t rattle. However, there was an obvious gap at the rear mating of the receivers. The rear and front takedown pins fit and functioned properly with no grinding needed. The upper receiver was equipped with forward assist. The charging handle and bolt-carrier group slid out of the receiver smoothly. The charging handle was machined billet and anodized.
The bolt carrier group was impressive, a custom design by POF-USA that requires little to no lubrication because of a nickel-Teflon plating. It was integrally keyed and uses a custom-designed roller-cam pin that was also NP3 coated. The bolt was chrome plated and heat-treated to mil-spec standards. Disassembly and lubrication were simple to perform, and POF-USA recommends additional lubrication of these parts during break-in.
The three-position short-stroke-piston gas system is also a POF-USA proprietary design and was extremely easy to disassemble clean and lubricate. POF designed this gas system to cycle by the “push” of the rebounding bolt-carrier group during the cycling of the gun. That eliminated the use of springs usually associated with push-rod systems, which resulted in a five-piece proprietary gas system (a pinned single-piece gas block, the gas plug, the gas piston, the chrome-plated operating rod, and the custom milled bolt-carrier group). A three-position gas valve moved easily and crisply and disassembled easily. The gas piston was easily slid out, followed by the operating rod. Excluding the bolt-carrier group, there were only three removable pieces that would need to be maintained, and we found that all were easy to clean and lubricate. However, these three parts operate in alignment via a channel or tunnel, and because of exact tolerances, this channel and the bore must also be clean and lubricated. Fortunately, this area is not prone to dirt, but it should be maintained. Doing so was straightforward.
Re-assembly was done in record time: Insert the push rod through the top of gas block, ensure it is fully seated, slide the gas piston in through the open top of the gas block, and then slide the gas plug into place through the open end of the gas block. It is held in place by spring-loaded detents built into the gas plug.
The lower receiver was billet machined aluminum with an integrated oversized trigger guard. The ambidextrous bolt release felt precise and secure, with no loose parts. The MagPul MOE pistol grip was secure and offered a good grip and bonus storage compartment. A POF-USA drop-in nonadjustable 4.5-pound single-stage competition trigger system felt smooth and consistent. Last, the lower receiver comes with KNS Anti-walk pins, and the MagPul PRS buttstock could be adjusted for length of pull and cheekpiece height.
The only area that drew some concern was the cost of equipping the already pricey rifle with a sighting system, since it didn’t come with anything, thus, couldn’t be used out of the box.
Handling & Controls
The DPMS LR-308 AP4 Carbine was lighter at 10.25 pounds with an empty magazine and 11.25 pounds with a full load of ammo. It was easy to set up and shoot from the bench. The factory quad rail came with smooth rail covers, allowing the AP4 to settle into the sandbags nicely. Length of pull was easily adjusted with the mil-spec 6-position stock. The scope mounted on top of the receiver easily once we removed the factory-installed A3 carry handle. The direct-impingement gas system cycled the action without any malfunctions. The bolt hold open and bolt release worked every time. The trigger was predictable and broke well for a mil-spec single-stage unit.
The POF P308-20 weighed in at 10.8 pounds with an empty magazine. Mounting the 13-inch-long Sightmark scope was simple and didn’t require removing any other parts since the gun did not come with back-up iron sights (BUIS) or a carry handle. The 14-inch free-floating monolithic top rail system made mounting optics easy and more adjustable to desired eye relief. The POF-USA nonadjustable competition trigger was smooth, light, and consistent. The bolt hold open and mag-release functions operated without issue, and no external parts became loose or required alteration.
Close Quarters Handling
In a mock CQB trial, we tested maneuvering each unloaded rifle in standard 40-inch hallways throughout a furnished house. With the stock collapsed, the DPMS LR-308 AP4 Carbine measured 34.5 inches in overall length — short enough to make maneuvering in hallways possible. With a loaded mag, a red dot, a forward grip, and a three-point sling, holding the DPMS at the ready position for extended periods was challenging. The A2 rear sight and front post were effective in lighted conditions, but we had trouble using them in low lighting. To use it in CQB, we’d swap the A2 carry handle sights for a dot or some other low-light solution. We also entered and exited a vehicle with the reasonably handy rifle. In contrast, the POF P308-20 was too heavy and too long for CQB work, in our estimation.
At the Range
With the guns field-prepped, measured, and initially assessed, we next began to shoot them for accuracy and to assess their function and reliability. Each gun was fired with 100 rounds of three types of ammo. Tests were conducted on six separate days at three different gun ranges, using the same shooter to ensure consistency. We fired three different bullet weights from three different manufacturers. The test rounds were Hornady’s 168-grain 308 Winchester Boat-Tail Hollow Point (BTHP) Match round; a 173-grain M118 Match round made at the Lake City plant; and a bulk-packaged Austrian 7.62x51mm NATO round, with 146-grain HP-74 nomenclature. We used the same scope on both guns, transferring a Sightmark SM13017 4-16×44 Tactical Scope in a set of 30mm rings between the rifles. We also used a new device to capture velocity data, the MagnetoSpeed V3 Ballistic Chronograph.
The POF P308 rifle achieved the best groups across all three ammo types. The POF shot a 1.0-inch group average with the Hornady Match 168-grain boattails, followed by 1.3-inch groups from the Lake City M118 173-grain load. The largest groups were recorded by the Austrian HP-74 NATO at 1.8 inches. Although the POF P-308 did shoot the tightest groups by about a quarter-inch per load, the POF P308 periodically had trouble cycling the Lake City M118. There were no failures encountered with the other two types of ammo. The DPMS completed the tests without any function failures; however, during range testing, the ambidextrous selector switch became loose and fell off the gun. Off the bench, two Gun Tests testers new to the AR platform felt comfortable with all operational aspects of the DPMS LR-308 AP4 carbine.
Our Team Said:
The team agreed that both guns were well made; the quality was on par for commercial production guns.
The POF P308-20 lost points for its failures to feed with one of the test ammos and was not ready to shoot (accurately) out of the box because it didn’t come with any sights. And for twice the price of the DPMS LR-308, we expected much better accuracy than we achieved. On the plus side, the POF P308 has superior internal execution with the company’s advanced coatings, and we liked its advanced rail system and its modern profile.
The DPMS LR-308 AP4 would be Our Pick in spite of the isolated issues surrounding our test gun’s rear takedown pin and loose selector switch. It doesn’t get a top grade because of these niggling issues, but we had no malfunctions with the gun whatsoever. The AP4 would make a great ranch rifle, scoring hog kills easily, right out of the box. The DPMS LR-308 AP4 Carbine is definitely a heavy hitter that’s highly configurable, compact, and lots of fun to shoot. In the current market, they can be bought for around $1000 counter price, and in our opinion, are worth the money.
Written and photographed by Rafael Urista, using evaluations from Gun Tests team testers.