PWS “Modern Musket” Direct Impingement AR

PWS “Modern Musket” Direct Impingement AR


ABOVE: The direct impingement Modern Musket harkens back to our early nation’s history.

It is no secret that the Eugene Stoner’s AR platform is the best selling rifle in the U.S. with many manufacturers jumping on the bandwagon in recent years by offering their versions. It seems the ARs adaptability attribute is also its most abused quality. Primary Weapons Systems (PWS) is seeking to counter balance this trend towards over accessorized ARs with their “Modern Musket” direct impingement AR. That is right, PWS, the standard bearer for the long stroke piston driven AR, has introduced a direct impingement AR platform.

The Modern Musket joins PWS’s existing MK1 5.56mm, MK2 7.62x51mm long stroke ARs, T3 rimfire, and recently introduced MK3 Precision Bolt. PWS is known as a leader in the quest for improving the AR operating system and cultivates an almost cult following based on superior customer service, unique interaction style with consumers and, most importantly, coming through on their promise of a superior AR rifle. PWS did not hang their hat on going with the typical short stroke piston in lieu of Stoner’s original direct impingement (DI) AR design; they took the less traveled path by utilizing a long stroke operating piston. We will define long stroke as exemplified by the AK47 of having op rod connected to the bolt carrier whereas short stroke consists of a more complex arrangement of tapped gas imparting force to an op rod that impacts another part of the mechanism that acts on the bolt carrier. PWS did not stop with the long stroke piston in their tweaking of the AR; rather they insisted on top quality components as well modifying the buffer tube connection to the receiver as well as bolt carrier design.

The PWS Modern Musket rifle was used from barricades and simulated cover while engaging multiple targets.

While PWS long stroke AR rifles are well-known and respected, their entry into the direct impingement AR market is presently still relatively unknown. In the world of modern marketing it is nice to discover a product in the catalogue you feel should be the main story. The PWS Modern Musket is such a product. Any law enforcement agencies, security conscience citizen, or modern sporting rifle (aka AR-15) connoisseur should consider the PWS Modern Musket. PWS has chosen to take advantage of lessons learned with their long stroke MK1 and MK2 ARs and apply this to the Modern Musket.

The homage paid by naming their new DI AR Modern Musket is based on the AR’s ever growing popularity in the U.S. market as well as PWS’s belief that every freedom loving American should own an AR just as we depended on gun ownership at the birth of our nation’s independence. The same PWS principles that guided their long stroke AR journey are present in the Modern Musket. Only after a thorough survey of the topic did PWS move forward. The Modern Musket DI-16 tested for this article is chambered in .223 Wylde. A quick word about the DI-16’s .223 Wylde chambering is in order. The .223 Wylde was designed as a match chambering for semiautomatic rifles. It will accommodate both .223 Rem. and 5.56mm ammunition. It is relieved in the case body to aid in extraction and features a shorter throat for improved accuracy. As most know, the 5.56mm is not synonymous with the .223 Rem. chambering. Generally, it is advised as acceptable to fire .223 Rem. in a 5.56mm, but not the other way around. The .223 Wylde was meant to give a slightly tighter body spec than 5.56mm, but a bit looser than .223 Rem., while retaining a longer lead/throat. In effect, the .223 Wylde is a hybrid splitting the difference between the 5.56mm and .223 Rem. while extending benefits in terms of accuracy and reliability.

The PWS Modern Musket rifle was used from barricades and simulated cover while engaging multiple targets.

The Modern Musket is a no nonsense AR rifle. PWS chose to use a Magpul MOE buttstock and pistol grip with the Modern Musket. The collapsible buttstock is easily adjusted for length of pull and/or transport. It is also one of the lighter AR versions on the market, especially considering that it features a full length rail and 16-inch barrel, weighing less than 7 pounds. The low profile PWS gas block found in Modern Musket rifles is machined from heat-treated tool steel and is much lighter than standard low profile gas blocks helping to shave weight. A minimalist PWS KeyMod rail design measuring 15 inches further assists in weight savings. The PWS rail system permits the barrel to be free floated for better accuracy. The Modern Musket shows versatility in satisfying customer needs by not using full length quad rails, but instead a lower profile handguard with adjustable KeyMod Picatinny rail sections. The KeyMod handguards minimizes weight and prevents the Modern Musket from being front heavy impacting handling, yet allows for effective cooling of the barrel and secure mounting of sling swivels and flashlight attachment interface. The minimalist approach for rails still allows plenty of room for VFG, bipod and lights/lasers if so needed. Not all weapons need rails and an array of accessories to be considered viable. It is often best to let the end user how to set up their specific rifle.

The DI-16 variant features a 16-inch 1:7 twist barrel contributing to an overall length of 36.5 inches with stock extended and 33 inches collapsed. PWS uses high quality chrome moly barrel blanks that they turn themselves; then Isonite treated inside and out for hardness and corrosion resistance and then threads on their proprietary muzzle device design. The rifle weighs 6 pounds 12 ounces pounds empty. The trigger used with the Modern Musket is a definite upgrade over typical Mil-Spec variants; it is an ALG Defense’s Quality Mil-Spec trigger for a smooth pull and a crisp break.

A supplied Lucid HD 7 is a nod to realism that red dot sights are here to stay. Most will add flip-up back up iron sights for peace of mind.

PWS’s experience in developing their piston ARs is carried over into the Modern Musket. They eliminated the typical AR castle nut method of attaching the carrier tube to the lower receiver using indexing screws instead. PWS has designed an enhanced buffer tube with an extended lip to support the carrier at rest, allowing for smooth entry into the buffer tube upon cycling of the action. The buffer tube has QD sling attachments machined directly into the aluminum, is enhanced with four integral drain holes in addition to a rear drain hole thus allowing more water to escape the system, as well as fluting for more debris tolerance in adjusting the Magpul rear stock. Lastly, their buffer tube uses a H2 buffer consisting of a tungsten weight housed in a steel body coated in nickel Teflon for reduced friction.

The Modern Musket’s bolt carrier is precision machined, Isonite treated and sport unique features that increase the reliability of the DI AR-15 platform. These features are increased mass to extend dwell time and delay unlock. As a result, the PWS bolt carriers allow chamber pressure to be greatly reduced for easier extraction. Gaps and channels between skid pads allow for fewer points of contact within the receiver thus resulting in less friction and keeps debris from interfering with function. A BCM Gunfighter charging handle tops off PWS’s effort in improving the bolt carrier by giving the user better purchase in manually operating the Modern Musket’s bolt. Inexpensive charging handles tend to twist and bend when put under stress as expected with a rifle designed for hard use either in training or deployment.

The PWS KeyMod handrail maintains adaptability while streamlining the forend as well as allowing the barrel to be free floated on the Modern Musket.

PWS’s most significant upgrade for the Modern Musket is shipping it standard with Lucid’s HD 7 red dot optic mounted on the upper receiver’s flat top rail. Let’s face it – customers will end up foregoing iron sights as the primary means of aiming their Modern Musket and mount a red dot of some sort. PWS accepts this truism and equips the Modern Musket with a sound choice for a red dot straight out of the box. End users can still mount back up iron sights of their choice with Magpul sights the most likely option. Water proof, shock proof and fog proof, the 13 ounce Lucid HD 7 red dot sight allows users to cycle through four different reticles and is covered by a lifetime warranty. Lucid founder, Jason Wilson, was convinced there was a market for simple, reliable optics at an economical price. MSRP for the Lucid HD 7 is $249. His plan was to design a scope here in the United States, and then manufacture it overseas to keep the price reasonable. The Lucid HD 7 features a rubber-armored aluminum body, lower 1/3 co-witness for your AR-15’s iron sights and an integral scope mount. The Lucid HD 7 takes a single AAA battery that front-loads into the base of the unit and provides an estimated 1,000 hours of use. The HD 7 has a two hour auto shut off. On the left side of the base is the power button and up/down brightness controls featuring seven settings as well as an auto brightness setting. Also, on the left side of the HD7 is the reticle selection turret, which gives you four options: a 2-MOA dot, a 2-MOA dot surrounded by a larger circle, a crosshair, or a chevron. Elevation and windage turrets use 1/2 MOA adjustments.

Ammunition tested with the PWS Modern Musket was a combination of 600 rounds of Black Hills Ammunition, Federal Premium, American Eagle, Hornady TAP loads and Winchester 55 grain FMJ. Readers deserved to see what base line accuracy was like with the Modern Musket: thus, the decision to mount a Leupold Mk 4 3.5-10x scope before re-attaching the Lucid HD 7 for the remainder of the T&E. The Modern Musket kept all loads tested under 2 inches at 100 yards; this includes FMJ with premium loads hovering around inch groups. This accuracy level justifies permanently mounting a magnified optic such on the flattop upper if a user desires. Of course, a red dot optic such as Lucid HD 7 is viable as well. Accuracy test protocol consisted of 3 five-shot groups with each ammunition type and group sizes were averaged. Velocity figures ranged from 2,800 fps to 3,000 fps over a RCBS chronograph.

PWS’s bolt carriers have performance enhancing features such as increased mass, gaps and channels between skid pads, and a BCM Gunfighter charging handle.

With the magnified optic removed it was decided to expand normal T&E protocol. After sighting in the Lucid HD 7 at 50 yards, the PWS Modern Musket was taken to the Echo Valley Training Center’s (EVTC) 360 and “Jungle Walk” ranges. Training scenarios involving team tactics along with patrolling to contact allowed the Modern Musket to shine in terms of potent firepower and accuracy. Firing from unorthodox positions while working around range vehicles showed why the light weight PWS Modern Musket and Lucid HD 7 are such a good combination. The PWS is easy to manipulate and the HD 7’s red dot is not dependent on a specific eye relief distance to be effective in accurately placing rounds on target. The Lucid HD 7’s red dot sight assisted in engaging targets at close distances with the red dot easy to pick up rapidly. The HD 7 red dot sight offered the capability to engage multiple targets in rapid sequence compared to open sights, while at the same time providing adequate accuracy out to a couple hundred yards on man-sized targets yards due to the red dot not obscuring the target due to the dot not being that large.

A huge benefit of choosing an AR for use is the multitude of magazines available from various manufacturers. This author has come to trust Brownells for metal AR magazines and Magpul for polymer variants. The Magpul 40-round PMag is steadily growing as a favorite among the higher capacity AR magazine variants due to its track record of performance involving multiple weapon reviews. Along these same lines nearly every tactical webbing gear manufacture in the U.S. offers products to carry AR magazines ranging from chest rigs, vests, thigh subloads, belt pouches etc. Go-to brands are US Palm, High Speed Gear, Velocity Systems/Mayflower, and BLACKHAWK!. A simple offering from BLACKHAWK! is their bandoleer style pouch. It will appeal to many with its ability to accommodate two pistol magazines in conjunction with four AR magazines. The BLACKHAWK! bandolier can be grabbed in a hurry and slung over your shoulder while also hastily grabbing the Modern Musket. For civilians, four spare magazines plus one in the Modern Musket is plenty to solve most issues that would call for the PWS DI AR in
the first place.

Modern Musket with Lucid HD 7 sighted in using Champion front pedestal and bags.

All Modern Musket features are intended for maximizing effectiveness during a fight or realistic training on the range. The key component in a fighting rifle is reliability. No matter how accurate or powerful chambering a rifle is if it does not work 100% of the time it is a liability. As with any personal weapon, selection of a fighting rifle is as personal as it gets and individual preferences and prejudices will decide interest level in the PWS Modern Musket. The Modern Musket is intended for serious practitioners who plan on using it for patrolling, training, or defense. If you ever envisioned a scenario responding to a bump or other commotion and have to grab a rifle and bandolier of magazines on the way to respond, then the PWS DI AR is more than worthy of consideration of the Modern Musket nomenclature.

Sites of interest

Primary Weapons Systems (PWS)

Lucid Optics

Brownells Inc.

The Modern Musket was tested with Lucid HD 7 and Leupold Mk 4 3.5-10x optics.
The 16-inch barrel DI-16 Modern Musket chronograph 55-62 grain bullets at 3,000+ fps.