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Here Comes the Revolution: Patriot Ordnance Factory’s Latest Falls into the Middle of an Impressive Trio

By Tom Murphy, Photos Courtesy Patriot Ordnance Factory

The Patriot Ordnance Factory (POF) Revolution rifle is a .308/7.62x51 caliber rifle that handles and feels like a .223/5.56, because it’s virtually the same size and weight as the smaller caliber. With its empty weight coming in at just over 7 pounds, it’s slightly lighter than their 5.56 NATO Warhog and just .3 pounds heavier than their 5.56 P45 Edge. POF managed to reduce weight by using some 5.56 parts; namely the bolt carrier and other 5.56 equipment, allowing a shorter overall receiver and reduced weight. The Revolution frame shares parts commonality with the smaller rifle by using the charging handle, bolt carrier, cam pin, buffer, heat sink barrel nut, handguard and five-position gas piston operating system of the 5.56. The barrel extension, bolt assembly, upper receiver and lower receiver are exactly the same size as those of an AR-15. That makes for a .308 that shoots like an AR.

The Revolution features POF’s free-floating monolithic Edge handguard that slides on and keeps the shooter’s grip and accessories from weighing on the barrel. It’s five times thicker than a standard flat top rail. The construction of the handguard directs stress upward and back over the upper receiver.

POF has developed a dual extraction technology that incorporates four small channels cut into the chamber walls that allow a small amount of gas pressure to flow back against the neck of the cartridge. This assists in extraction by breaking the seal between the cartridge case and the chamber and pushes the spent case to the rear as the extractor pulls the case.

The chrome molybdenum barrel is nitride heat-treated for strength and accuracy. Chrome moly has an excellent strength-to-weight ratio and is considerably stronger and harder than standard 1020 steel. A nitride heat-treated three-port muzzle brake controls gas dispersion and reduces muzzle flip. This makes for faster second shots.

The non-adjustable drop-in trigger is set to a 4.5-pound let-off. It’s installed in a hardcoat-anodized aluminum housing. The trigger, disconnect and hammer are all nitride-heated to 70 Rockwell, which is right at the top of the Rockwell scale of hardness (the maximum is 72R). The trigger and hammer pins are provided by KNS Precision and are of the anti-creep design.

The 3-inch heat sink barrel nut completely encompasses the chamber and throat area of the barrel where gas temperatures are highest. Made from aluminum, its heat transfer qualities are much greater than those of steel. The bolt carrier group is phosphate-nickel coated. Phosphate coatings are used on steel parts for corrosion resistance, lubricity or as a foundation for subsequent coating or painting. The bolt’s key is positioned behind the cam pin, which aids in controlling carrier tilt. The bolt, extractor and firing pin are hard chrome plated. Unlike most AR-15 square cam pins, which impinge directly on the upper receiver and cause wear, POF builds an NP3-coated roller bearing cam pin (NP3 is an electroless nickel/PTFE coating process that is self-lubricating, extremely hard and very resistant to wear).

The MIL-SPEC aluminum buffer tube has internal carrier extensions to ensure that the carrier is supported through its full travel. This prevents carrier tilt and stops premature wear of the buffer tube. There is also a detent that keeps the buffer tube from rotating.

POF incorporates an adjustable gas system that consists of the gas plug, gas piston and operating rod. This allows gas flow adjustment when fitting accessories like a suppressor. The gas system can be modified simply by rotating the gas plug through its five positions. The normal position is with the notch in the gas plug straight up. To reduce gas flow, rotate the notch 45 degrees to the right (muzzle facing you.). To turn the gas totally off, put the button on the top and the notch at the bottom. For use with a suppressor, the notch can be set to where the smooth side is on the top. There is a second suppressor position which is set by rotating the plug until the smooth side is 45 degrees to the left. This provides slightly more gas flow if the suppressor requires it.

The POF .308 Revolution is built on the company’s Gen 4 lower receiver. It incorporates:

 

Shooting the Revolution

All shooting was done with two brands of .308 ammunition; Black Hills 175-grain Boat Tail Hollow Point with a Sierra TMK bullet at 2,600 feet per second and 2,626 foot-pounds of muzzle energy; and ATK XM118 Long Range military ball manufactured in 2002 by newly-named Orbital Alliant Techsystems. The ATK ammo was manufactured to MIL-DTL-32288 for long-range sniper work. The earliest “LR” headstamped ammo was 1995, but LR didn’t become available in this form until ATK took over operation of Lake City Army ammunition plant in 2001. XM is the civilian counterpart to the M118LR military round.

The rifle was fitted with a Trijicon AccuPoint 2.5-12x42 MIL-dot scope. Initially it was sighted in at 100 yards for firing for familiarity, but then the zero was raised to 200 yards. The scope was then dead on at 50 yards and 1.5–2 inches high at 100 yards. From the first shot, the gun and the Magpul PMAG 20 Gen M3 fed flawlessly. As a matter of fact, they even ran fine after being caught in one of the famous Las Vegas dust storms that passed through the range. (No, I put the rifle in the truck, but managed to leave the mag on the shooting bench.)

A number of people shot the Revolution, including the rangemaster and an NRA instructor. After working up the gun, both were able to keep all shots in the 10-ring at 100 yards and all but one flier in the black at 200 yards.

Operational Reliability

In 2012, the San Bernardino, CA, Sheriff’s Department began a long-term test and reliability study on POF’s .308 14.5-inch-barreled select-fire rifle. The initial test involved 35,480 rounds of various brands of ammunition being fired through the rifle. After discussions with the POF factory, the decision was made to continue the test to obtain information on long-term reliability. A report was made on the attempt to “fire to failure”—whether it be due to decreasing accuracy or mechanical failure. At round count 66,900, the head of the operating rod fractured and broke off, causing the rifle not to cycle. However, the rifle was capable of firing by hand-cycling the action. After a new op rod was sourced, the rifle had another 33,100 rounds shot through it.

As of this article, the test rifle has been returned to POF, where it is still being tested. The round count recently reached about 88,000, when a lug finally broke off the bolt. The bolt has been replaced, and the Revolution is still going bang.

Revolution .308 Specifications

Part #: 01235
UPC: 847313012357
Caliber: 7.62x51mm NATO/.308 Winchester
Chamber: E2 Dual Extraction Technology
Action: Semi-auto, short-stroke gas piston system
Weight: 3.31kg/7.3lb (empty)
Barrel: 16.5in/36.83cm match-grade nitride heat treated
Rifling: 1:10 5/8x24 barrel threads
Length collapsed: 34in/ 86.36cm
Finish: Black anodized
Gas block: Adjustable five-position
Handguard: 14.5-in M-LOK MRR free-floating rail
Muzzle device: Three-port muzzle brake
Trigger: 4.5-lb pull POF-USA drop-in trigger system with KNS anti-walk pins
Furniture: Mission First Tactical
Accuracy: MOA w/proper ammo
Fire control: Gen4 billet lower receiver | Ambidextrous bolt release | Ambidextrous safety selector | Ambidextrous bolt catch | Ambidextrous magazine release
Maintenance: Remove gas plug to clean block and piston components without removing handguard. No tools required. Uses standard receiver/carrier group field strip procedures.
Includes: High phosphate nickel-coated bolt carrier group | Chrome-plated bolt | Seven-position anti-tilt buffer tube | Magpul 20-round magazine | Teflon receiver tension screws

How the POF .308 Revolution was Tested

Maintenance throughout the testing period consisted of two cleaning sessions and an occasional application of gun oil. No other maintenance was performed. Below is the Sheriff’s report on the test:

Test duration: 09/2012–12/2014 (26 months)

Number of rounds fired: 68,580 (33,100 fired after the test)

Number of malfunctions: 33

Malfunction types: Failure to feed, failure to extract, failure to eject, double feed

Note: No malfunctions were experienced until the round count surpassed 23,000 rounds. Extraction problems were caused by part fatigue, not stuck rounds. No new part-related malfunctions were recorded from round 35,900 until it reached round 66,900.

Ammunition used: 7.62x51mm | Federal 168-grain Match | Federal 168-grain Premium | Federal 150-grain FMJ | Federal 149-grain FMJ | Winchester 150-grain Power Point | WPA 145-grain FMJ | TEN-X 125-grain Frangible | Speer 168-grain LE Gold Dot Soft Point | Hornady 155-grain Steel Match BTHP | Fiocchi 150-grain BTSP

Initial accuracy tests showed 100-yard accuracy of .473 to .753 inches and 500-yard accuracy of 3.76 to 6.01 inches.

Accuracy at round count 24,000: .851 inches at 100 yards and 5.12 inches at 500 yards

Accuracy at round count 66,900: 1.12 inches at 100 yards and 5.98 inches at 500 yards

Average muzzle velocity throughout the test ran from 2,375 feet per second when new to 2,384 feet per second after 66,900 rounds.

During the test, the following parts were replaced at the listed round count:
Buffer spring: 23,500
Gas piston: 28,600
Ejector spring and buffer: 29,800
Extractor spring: 34,280
Op rod: 35,900
Op rod: 66,900

Trijicon AccuPoint 2.5-12.5x42 Riflescope

We fitted a Trijicon AccuPoint to the Revolution for the testing. The AccuPoint is available with four different reticles—triangle post, duplex crosshair, MIL-dot crosshair and MOA dot. This scope had the MIL dot reticle with a green dot. The AccuPoint uses a combination of advanced fiber optics and self-luminous tritium. The dual illumination lets the fiber optic light collector illuminate the aiming point, automatically balancing the brightness with the shooting conditions.

Tritium is the isotope of hydrogen with an atomic weight of three. It is produced most effectively by the nuclear reaction between lithium-6 and neutrons from nuclear fission reactors. Trijicon uses tritium in their front sights. They use about 12mCi (millicuries) of tritium dissolved in a phosphor liquid contained in a small glass vial. The current cost of tritium is almost $30,000 per gram.

The tritium illuminates the aiming dot even in total darkness. A manual adjustment will dim the aiming point to set the reticle brightness according to personal preference or the surrounding conditions. A dial on the top of the scope makes adjustment quite easy.

All AccuPoint scopes feature the following:

AccuPoint scope controls and adjustments include the following:

 

Trijicon advocates shooting with both eyes open. Glyn Bindon, Trijicon’s founder, was the first to develop a method of using both eyes when using a magnified scope. He called it the Bindon Aiming Concept (BAC). Basically, it consists of focusing on the target and bringing the scope to your dominant eye. This will allow you to make an accurate shot on a moving target and engage a stationary target quickly.

This article first appeared in Small Arms Review V21N7 (September 2017)
and was posted online on July 21, 2017
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