POF P-308 state-of-the-art .308 battle rifle: there are still those who want a .308, and this POF product combines futuristic looks with a short-stroke piston operating system in a distinctive package.
This AR-15's method of operation has been subjected to a great deal of criticism. While the bolt carrier key can be cleaned by the operator, usually by means of a tobacco pipe cleaner, the stainless steel gas tube cannot be successfully maintained by a soldier in the field, and its replacement requires special tools and training. As the original 20-inch barrel has been compressed to 14.5 inches in the M4 configuration so popular with Coalition troops in the Middle East, the problems associated with this portion of the M16 system have increased.
Reducing the length of the gas tube shortens the gas pressure curve and increases the potential for bolt bounce and firing out of battery, short-stroking, feeding malfunctions, increased wear on the reciprocating components because of faster cyclic rates and a greater recoil impulse. Many of these problems can be reduced or eliminated by use of a short-stroke gas piston method of operation.
SHOTGUN NEWS recently received a fascinating rifle that is based upon the AR-15 configuration, but using a short-stroke piston method of operation and chambered for the battle-proven 7.62x51mm NATO (.308 Win.) cartridge. Others are looking closely at this potent new battle rifle, including some groups within the U.S. military's special operations community (USSOCOM).
Manufactured in the United States by POF-USA (Dept. SGN, Patriot Ordnance Factory, Inc., Glendale, Ariz. 85310; phone: 623-561-9572; fax: 623-321-1680; E-mail: email@example.com; website: www.pof-usa.com), the P-308, as it has been designated, is semiautomatic-only. It has been demonstrated over and over again in rifles such as the M14, FN FAL and H&K G3, that the selective-fire feature in a lightweight 7.62x51mm NATO rifle is uncontrollable with very low hit potential.
The P-308 rifle sent to SGN for test and evaluation has a 16.5-inch (419mm) barrel. This Rock Creek 5R, 4150 MIL-B-1159, chrome vanadium steel barrel has five grooves with a l:10 right-hand twist. Starting with a Rockwell C hardness of 28-32, alter heat treating, the barrel hardness is 68 Rockwell C. The barrel has a black nitride finish and is fluted to reduce weight, increase strength, increase the surface area for improved heat dispersion and because it looks good.
The barrel extension is machined from high-grade steel and heat treated for an increase in strength of more than 30% over existing MilSpec and features an enhanced feed ramp to increase feeding reliability. Overall length of the rifle is 38 inches (965mm). The weight, empty, is 8.75 pounds (3.97kg). Two other barrel lengths are available: 20 inches and 14.5 inches with a permanently attached muzzle device. The manufacturer's suggested retail price, in. any barrel length and complete with one 25-round magazine, is $2,500.
The muzzle brake installed on our POF P-308 test Specimen is just that: a muzzle brake, not a flash suppressor. As a consequence of the laws of Newtonian physics, devices attached to the muzzle end of a rifle barrel invariably are successful in addressing only one parameter. In general, infantry rifles, especially those intended for CQB (Close Quarters Battle), are better served with a muzzle device that reduces the flash signature and the consequent position disclosure of the operator.
However, when firing from long distances, addressing muzzle jump and perceived recoil of the weapon may be more important. The P-308 muzzle brake has a large port on each side and three smaller holes on top, two paired equi-distant from each other and one offset to right to drive the muzzle downward for a right-handed shooter. There are four impact tips at the front.
A POF proprietary design that resembles the AK74 unit, this brake is machined from 4140 chrome moly steel, nitride heat treated and finished with Robar's NP3. The reduction in the recoil impulse is significant, although the muzzle blast is also significant.
Military end users can opt for any number of optional muzzle devices that successfully address the flash signature. A jam nut instead of washers was used to attach the muzzle brake to the barrel, as it's easier to install in this manner and puts less stress on the barrel.
POF upper receivers are machined from 7075 aluminum billet stock and POF claims they have 85% more wall thickness than most AR-15-type receivers, providing a substantial increase in strength and significantly reducing flex during the operational cycle. The solid aluminum billet results in more uniform dimensions with improved heat dissipation.
The short-stroke piston method of gas operation used on the P-308 rifle is similar to that found on the FN FAL series. The gas regulator has two positions, the normal setting marked "N" and the sound suppressor setting marked "S".
The "S" position bleeds more gas into the atmosphere. This is necessary because sound suppressors invariably increase the rearward impulse of the recoiling components as a consequence of the increased amount of blowback pressure they introduce into the system. Bleeding more gas into the atmosphere brings the cyclic rate on selective-fire models back down to specified levels and reduces wear on the reciprocating parts of both selective-fire and semiautomatic-only versions of the P-308.
Another truly significant aspect of the entire short-stroke-piston-gas-operated POF rifle series is the amount of design engineering that was focused on the location of the "key" on top of the bolt carrier. Because of the key's position oil top of the carrier, behind the cam pin, its interaction with the push rod or rear end of the piston--results in carrier movement without any tilt on a flat linear plane.
This is important for two reasons. From the mechanical engineering perspective, the all too common issue of bolt bounce is almost completely eliminated. Secondly for safety and liability reasons, M16/AR-15 internal components cannot be installed in the POF system.
The upper receiver and a number of other components have NP3 plating. This process, an exclusive coating of the Robar Companies, Inc., (Dept. SGN, 21438 North 7th Avenue, Suite B. Phoenix, Ariz. 85027; phone: 623-581-2648; fax: 623-582-0059; e-mail: firstname.lastname@example.org; website: www.robarguns.com) is a surface treatment for metals and metal alloys that provides the appearance of satin electroless nickel by combining sub-micron particles of PTFE (polytetrafluoroethylene, i.e., Teflon) with autocatalytically applied nickel/phosphorus.
The result is a very accurate, dry-lubricated, low-friction surface that is extremely resistant to wear. As the PTFE is evenly distributed and locked into the nickel/phosphorous matrix, when wear occurs, fresh particles of PTFE are exposed to keep the surface lubricated. NP3 has a high lubricity and low friction co-efficient. No lubricants are required on any metal surface so treated and powder residue and carbon fouling can be easily removed with a dry cloth. NP3 has a non-reflective satin gray appearance.
At my request, the other major components of the P-308 used in our test and evaluation were treated with a foliage green (used in the U.S. Army's ACU uniform) Polymax finish. Robar's Polymax, a polymer coating designed specifically for firearms, can be applied to steel, stainless steel and aluminum surfaces.
With 2H in pencil hardness, Polymax is impact, chemical, water, mar and abrasion resistant with excellent adhesion. Available in an almost infinite variety of custom colors and camouflage patterns, it can withstand 1,000 plus hours in a 5% salt spray and 500 hours in 100% relative humidity without failure.
The P-308 barrel is press-fit, rather than slip-fit, to the upper receiver as this provides a more positive lock between these two components. Additional features of the POF upper receiver include a heat-treated NP3-coated, bolt carrier with an integral key. The bolt, cam pin, firing pin, and Badger Ordnance charging handle with tactical latch are all MilSpec and hard chrome plated to increase service life and facilitate cleaning.
As the method of gas operation is by short stroke piston, the bolt has no gas valves (or rings) as found on the M16/ AR-15 series. These gas valves must be frequently replaced, as they quite literally burn up. The P-308 bolt head is made from Carpenter 158 and the carrier from 8620 steel. Both are carburize heat treated as per MilSpec.
An especially unique feature of all POF AR-type rifles is the heat sink barrel nut, which dissipates heat away from the critical throat, upper receiver, bolt and bolt carrier areas and increases the rifle's service life. This heat sink barrel nut, acting as an extension of the receiver, increases the upper receiver's overall strength and diminishes flex.
It also provides strength to the free-floating MIL-STD-1913 quad rail system. The patented POF quad rail system (or MRR--Modular Railed Receiver), which is the front half of the two-piece upper receiver, has an 80% increase in wall thickness and replaces structural integrity that was lost when the M16A1 carrying handle was removed from subsequent models.
We installed ERGO Full Cover Rail Covers [aka "ladders"] (Falcon Industries, Inc., Dept. SGN, P.O. Box 1690, Edgewood, N.M. 87015-1690, phone: 505-281-3783 or toll free 877-281-3783; fax: 505-281-3991; E-mail: orders@er gogrips.net; website: www.ergogrips.net) on the POF P-308 MRR. Made of Santoprene, in black, coyote brown, dark earth, foliage green, and OD green, these rail covers come in three lengths: short (covers five rail slots), medium (10 slots) and long (15 slots). They are widely used by armed professionals everywhere.
An ERGO ambidextrous pistol grip was also installed on our P-308. It features smooth textured finger grooves, an integral rear upper extension to support the web of the hand, and an overall textured finish to minimize slippage.
The POF P-308 lower receiver is also machined from 7075 aircraft-grade aluminum alloy billet stock. I was at the POF factory while 7.62x51mm NATO lower receivers were being milled on sophisticated CNC machinery and the precision and quality control involved in their fabrication was impressive to observe.
The P-308 lower receiver's magazine well is both enlarged and flared to facilitate installation of magazines under high-stress environments. The trigger guard is enhanced by enlargement-and, in my opinion, strengthened significantly by its one-piece configuration. It's large enough to permit the use of gloves without the necessity of a hinged bottom, which structurally weakens that area of the lower receiver. The selector lever, magazine catch/release and the bolt/ release controls are ambidextrous, with release buttons on each side of the lower receiver.
A Geissele Automatics LLC (Dept. SGN, 1920 West Marshall Street, Jeffersonville, Pa. 19403: phone: 610-272-2060; website: www.geissele.com) Match Rifle Model Hi-Speed National Match Dual Stage Trigger was installed in the P-308. William Geissele also produces the Super Select-Fire (SSF) and Super Semi-Automatic (SSA) non-adjustable combat triggers for the M16/AR-15 series.
Not only great trigger systems for National Match shooting, Geissele's triggers have demonstrated their worth on the battlefield in the Middle East for military sniper applications. I prefer his Hi-Speed Dual Stage triggers--either the Match Rifle Model we used or the Service Rifle or DMR models--as the parts are not encased in a "cartridge," which traps dirt and thus the trigger mechanism will function reliably even in high dust environments.
The Geissele Hi-Speed National Match Dual Stage Match Rifle trigger, which can be identified by its stainless steel springs, features a high-speed hammer that provides a 50% lock-time reduction over standard hammers. The short first stage pull is followed by an exceptionally clean and sharp second stage let-off.
The adjustable pull weights are 1.3 to 2.5 pounds in the first stage and 4 to 14 ounces in the second stage. We adjusted the second stage for the maximum 14-ounce pull. This trigger costs $279 and is worth every penny of that, as the trigger pull of a precision rifle system is one of the most important factors in maximizing the system's accuracy potential.
It has been conventional to design caliber 7.62x51mm NATO magazines for a capacity of 20 rounds. The newly designed P308 magazine is a two-position-feed. staggered-column, detachable box with a capacity of 25 rounds. While this provides the operator with five additional rounds, the rifle will often monopod on the magazine when fired from the low prone position and also sometimes when test firing off a shooting bench.
We also specified the installation of the new POF Precision Sniper Stock on our test specimen. Machined from lightweight 7075 aluminum alloy billets, this non-retractable stock has an adjustable cheekpiece, another absolutely essential feature when the rifle is deployed with high-magnification optical sights.
A proper, consistent and repeatable cheekweld is required to reach a scoped rifle's maximum accuracy potential. This stock was designed for a fairly large statured operator, as the length-of-pull, measured from the point of greatest curvature on the front surface of the trigger to the outside surface of the neoprene buttpad is approximately 14.5 inches.
I selected the popular 3.5-15x56mm NXS Nightforce (Dept. SGN, 1040 Hazen Lane, Orofino, ID 83544; phone: 208-476-9814; fax: 208-476-9817; website: www.nightfor ceoptics.com.) scope to interface with the POF P-308 for the accuracy portion of our test and evaluation, as this variable-power scope's more than four times magnification range (from 3.5X magnification to 15X magnification) closely matches both the rifle's and the caliber's tactical capabilities.
I used a set of Nightforce Ultralite rings and a GG&G Accucam Quick-Detach Mil-STD-1913 Scout Rail. The latter is designed to attach easily to all MIL-STD-1913 rifle rail interfaces with the GG&G MAD (Multiple Aperture Device) rear sight with Locking Detent.
This quick-detach rail raises the line of sight by a half-inch. Designed for a wide variety of optical sights, its integrated Accucam Quick-Detach lever system provides the operator the option to quickly utilize other optical devices. Its rail is machined from solid billet 6061 T6 aluminum alloy with a Type III hard coat anodized matte black MilSpec finish, its tension on the rifle's rail can be adjusted and it has zero repeatability of 1/2 moa. The Accucam mechanism itself is machined from solid billet 4140 steel and manganese-phosphated matte black to MilSpec. The price is $158.95.
There are tactical applications for which the Nightforce 3.5-15x56 NXS scope would be very obviously overkill. An interesting alternative is the ELCAN SpecterDR Dual Role Optical Sight. Manufactured by Armament Technology Inc. (Dept. SGN, 3045 Robie Street, Suite 113, Halifax NS B3K 4P6, Canada: E-mail: email@example.com; website: www. armament.com) and distributed in the United States by ELCAN Optical Technologies (Dept. SGN, 1601 North Piano Road, Richardson, Texas 75081; phone: 972-344-8077, toll-free: 877-TXELCAN; fax: 972-344-8260; website: www.el can.com), the scope's salient feature is the ability to switch quickly back and forth from 1X to 4X magnification, ideal power settings for urban warfare.
The SpecterDR attaches to a MIL-STD-1913 rail interface using two quick-release throw levers on the right side for instant attachment and removal, as designed and manufactured by Atlantic Research Marketing Systems, Inc. (Dept. SGN, ARMS, Inc., 230 West Center Street, West Bridgewater, Mass. 02379; phone: 508-584-7816; fax: 508-588-8045; website: www.arms mounts.com).
At 1.3 pounds, the ELCAN SpecterDR is fairly heavy for a low-power tactical scope. The optical housing has a 32mm objective lens and an 8ram-diameter exit pupil, which provides really excellent vision at subdued light levels. It also provides truly rapid target acquisition at short, intermediate and moderately long ranges. The SpecterDR incorporates LED's for red dot (at the center of the crosshairs) and reticle illumination under CQB or low light level environments. Its ballistically compensated reticle consists of a crosshair with horizontal stadia lines for shooting at various ranges. A Vertical Subtention Optical Rangefinder (VSOR) is incorporated within the view of view.
The relatively long eye relief is 2.75 inches (70mm). The field of view at 1X is 26[degrees] and 6.5[degrees] at 4X magnification. There are well-designed backup iron sights on top of the scope housing. Consisting of a 5mm-diameter peep aperture rear sight and a 2.5mm wide post front sight, the emergency sights can be removed, if desired. This heavy duty piece of MilSpec optics carries a manufacturer's suggested retail price of $1,449. The ELCAN SpecterDR has been fielded by Canadian Coalition troops in the Middle East and has demonstrated its merits on the field of battle.
We intend to almost constantly employ this rifle with various high-quality, low-power tactical scopes, such as the ELCAN SpecterDR, or the Nightforce 3.5-15x56 NXS scope red dot and optical sights. The chance of their failure on an operation is statistically quite low. Nevertheless, they can fail almost always at the wrong time-and emergency iron sights are absolutely essential on any rifle deployed in warfare.
Designers and manufacturers of cutting edge optical mounting systems and tactical accessories, GG&G (Dept. SGN, 3602 East Stravenue, Tucson, AZ 85713, phone: 1-800-380-2540; fax: 520-748-7583; E-mail: gggaz@aol. com; website: www.gggaz.com) are suppliers to law enforcement agencies throughout the United Sates and US military units of all branches. Simply put, their product line is often incredibly innovative and always outstanding in quality.
From the wide array of rear sights available from GG&G, we selected their very popular MAD (Multiple Aperture Device) Back Up Iron Sight (BUIS) (#GGG-1006). A very low profile folding rear sight, it clears most optics. Its salient feature is four apertures of two different diameters on the same plane, which means they are zeroed to the same point of impact. Developed to fulfill a request from Naval Surface Warfare and used extensively by Coalition Forces in the Middle East, the superb MAD BUIS sells for $140.
This has been mated with a spring actuated flip-up front sight for tactical forearms (#GGG-1282). With just a push of a button this marvelous front sight can be deployed on target. Once deployed, it locks solidly into the upright position. It cannot be folded down without depressing the actuator button on the right side. It can be easily co-witnessed with red dot optics and it uses standard military sight components. The price is $156 and an optional Trijicon tritium front sight post can be ordered for an additional $50. (The same feature is available for the MAD BUIS for and additional $50 as well.)
I prefer, if possible, to deploy with a vertical foregrip on both pistol-caliber submachine guns and assault rifles chambered for intermediate-size cartridges, but they are also extremely useful when firing heavy .308 battle rifles from the sometimes necessary standing position.
I especially like the GG&G Vertical Foregrip (#GGG-1169), as it has several valuable ancillary features. CNC-machined from solid black Acetal cold polymer for durability and low heat absorption, it has a waterproof compartment that will hold either two AA or CR123 batteries or an M 16-type spare bolt assembly. O-ring-sealed, it can also be used to store three N-type batteries, firing pins, ejectors, extractors or other small components. No tools are required to open the tri-grip waterproof cap. With an overall length of 4.5 inches and a comfortable 1.25 inches in diameter, it costs only $32.50. It was easily attached to the 6 o'clock rail on the POF P-308 and, I am storing two CR123 batteries inside it.
POF carries a line of gear made entirely in the United Sates by Mayflower Research & Consulting, LLC (www. mayflower-rc.org), which is owned and operated by Travis J. Rolph, whose military experience includes 15 years in the US Army's 5th Special Forces Group. All of Mayflower's Cordura nylon product line is solution dyed, not piece dyed and fire-retardant. We used three of their products in our test and evaluation of the POF P-308 rifle.
The 42-inch rifle case has a center padded divider and thus will hold up to two rifles. It has four generically-sized magazine pouches, a small zipper accessory pouch, and Velcro on the outside for attaching departmental badges and ID tags. It costs $80.
We were also provided with single-magazine pouch that will accommodate belt sizes from 1 to 2 inches and has inside gripping material to prevent it from sliding on the belt. We also examined a police sniper vest with three magazine pouches and three larger, exterior pouches designed for laser rangefinders, mini-binoculars, Kestrel products and a portable GPS. It has shoulder loops for attaching other equipment and pouches and has an "H," rather than "X" strap matrix.
GAS-OPERATED, SEMIAUTOMATIC ACCURACY POTENTIAL
Using Federal Gold Match (catalog #GM308M) with a 168-grain BTHP Sierra MatchKing projectile, POF test engineers have generated some pretty impressive accuracy results with the P-308 rifle. Group dispersion has gone down to .35 moa at 100 meters on occasion, and consistently under .5 moa. However, those results were obtained with the rifle in a fixture and that's not comparable with the manner in which most precision rifles are tested, i.e., fired on rests, off a bench, by an experienced operator. We tested the POF P-308 in this latter manner using four different loads with some interesting results.
We commenced our test and evaluation of the POF P-308 rifle using a Black Hills (Black Hills Ammunition, Dept. SGN, Box 3090, Rapid City, S. Dak. 57709-3090; phone: 1-800-568-6625; fax: 605-348-9827; website: www.black-hills.com) Gold match-grade load with a Hornady 168-grain boattail hollow-point A-MAX match bullet.
These truly superb bullets feature an ultra low drag tip that raises the ballistic coefficient, a secant ogive profile that produces flatter trajectories, an improved tip shank that provides mechanical support to withstand extreme velocities, a swaged lead core with exceptional uniformity, a boattail angle and length unique to each caliber to maximize the ballistic coefficient and thus accuracy, and a jacket drawn to the tightest possible tolerance. These are match grade projectiles at the very highest level of quality and performance potential.
Shooting off the bench in the standard manner and with the Nightforce 3.5-15x56 NXS scope powered up all the way, our group dispersions were almost always 1.0 moa. This firing was from the magazine, and the stripping pressure will often result in vertical stringing on the target when test firing gas-operated, semiautomatic rifles, such as the FN FAL.
We continued with three so-called "TAP" loads from Hornady Mfg. Co. (Dept. SGN, Box 1848, Grand Island, Nebr. 68802-1848; phone: 800-338-3220; website: www.hornady. com). Hornady's .308 TAP (Tactical Application Police) ammunition was developed for the police marksman who prefers the increased bullet weight and barricade penetration of the .308 Win. cartridge.
This ammunition offers the reliable functioning and consistent performance that delivers match-grade accuracy. The 168-grain TAP bullet is a traditional match-grade weight with the advantages of a polymer-tipped bullet's terminal ballistics.
The smallest group dispersion achieved was .7 moa with Hornady's 168-grain TAP ammunition. This is excellent. Leaving the muzzle at 2485 fps, the 168-grain TAP projectile will penetrate up to 17 inches of tissue simulant. The 155-grain TAP load averaged .9 moa, with a muzzle velocity of 2633 fps and penetration up to 14 inches in tissue simulant.
The 110-grain TAP load, developed specifically for law enforcement applications, has a muzzle velocity of 3050 fps and will penetrate about 10 inches of tissue simulant. As a consequence, it will defeat Level 2 or better protective armor, but not come out the other side of the perpetrator shot, whether or not there is a vest panel in the rear. It produced I accuracy levels of about 1.2 moa.
This is a well-designed, precisely machined and finished, highly accurate, robust and reliable gas-operated, short-stroke piston, semiautomatic rifle that meets MilSpec in all regards. I can personally recommend the POF rifle series without reservations of any kind. It is both highly desirable and currently in great demand.
POF P-308 specifications
Caliber: 7.62x51 mm NATO (,308 Win.).
Method of operation: Locked-breech, gas-operated by means of a short-stroke piston with a two-position regulator, semiautomatic-only.
Feed system: 25-round, two-position-feed, staggered column, detachable box-type magazine.
Weight, empty: 8.75 pounds (3.97kg).
Length, overall: 38 inches (965mm).
Barrel length: 16.5 inches (419mm).
Barrel: Rock Creek 5R, 4150 MIL-B-1159, chrome vanadium steel barrel with five grooves and a 1:10 right-hand twist.
Manufacturer: POF-USA, Patriot Ordnance Factory, Inc., Dept. SGN, Glendale, Ariz. 85310; phone: 623-561-9572; fax: 623-321-1680; E-mail: firstname.lastname@example.org; website: www.pof-usa.com.
Manufacturer's suggested retail price: $2,500.
Finish: NP3 and Polymax from the Robar Companies, Inc., Dept. SGN, 21438 North 7th Avenue, Suite B, Phoenix, Ariz, 85027; phone: 623-581-2648; fax: 623-582-0059; e-mail: robarguns@earth link.net; website: www.robarguns.com.
Lightforce USA, Inc., Dept. SGN, 1040 Hazen Lane, Orofino, Idaho 83544; phone: 208-476-9814; fax: 208-476-9817; website: www.nightforceop tics.com.
ELCAN Optical Technologies, Dept. SGN, 1601 North Piano Road, Richardson, Texas 75081; phone: 972-344-8077, toll-free: 877-TXELCAN; fax: 972-344-8260; website: www.elcan.com.
Auxiliary iron sights and ancillary accessories:
GG&G, Dept. SGN, 3602 East Stravenue, Tucson, Ariz. 85713, phone: 1-800-380-2540; fax: 520-748-7583; E-mail: email@example.com; website: www.gggaz.com.
Falcon Industries, Inc., Dept. SGN, P.O. Box 1690, Edgewood, N.M. 87015-1690, phone: 505-281-3783 or toll free 877-281-3783; fax: 505-281-3991; E-mail: firstname.lastname@example.org; website: www.ergogrips.net.
Mayflower Research & Consulting, LLC; website: www.mayflower-rc.org.
Geissele Automatics LLC, Dept. SGN, 1920 West Marshall Street, Jeffersonvilte, PA 19403; phone: 610-272-2060; website: www.geissete.com.
Black Hills Ammunition, Dept. SGN, P.O. Box 3090, Rapid City, SD 57709-3090; phone: 1-800-568-6625; fax: 605-348-9827; website: www. black-hills.com.
Hornady Mfg. Co., Dept. SGN, P.O. Box 1848, Grand Island, NE 68802-1848; phone: 800-338-3220; website: www.hornady.com.
T&E summary: A well-designed, precisely machined and finished, highly accurate, robust and reliable gas-operated, short-stroke piston, semiautomatic rifle that meets MilSpec in all regards.
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|Author:||Kokalis, Peter G.|
|Article Type:||Product/service evaluation|
|Date:||Jun 20, 2009|
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