Gun Review: Primary Weapons System Modern Musket 14.5″ in .223 Wylde

    Review: Primary Weapons Systems Modern Musket 14.5″ in .223 Wylde

    As I mentioned in my article about the Diablo, I was able to get access to a couple of sexy new rifles from Primary Weapons Systems. The Modern Musket being one of them. Walt and Luke from BMC Tactical ( hooked me up with a demo “pre-release” version (obviously they are somewhat available now).

    The “Modern Musket” is Primary Weapons Systems’ first foray into making a Direct Impingement style AR. PWS is best known for their Long-Stroke Piston rifles (and just like the Diablo writeup, this article is not intended to extoll the virtues of one platform over another). What I will say is that PWS puts the same level of professionalism and technical expertise into their craftsmanship of this direct impingement weapon as in any of the others that I have had the pleasure to shoot.

    You may see a couple of recycled bits from the Diablo review, because, well, both the Diablo and Modern Musket use some of the same components. And I ran them at the same time.






    The model I got to play with was the 14.5″ version. Primary Weapons Systems also sells a version with 16″ barrel (all of the other components being the same).

    The rifle comes as a complete “out of the box” solution. Meaning it is intended to run as a great performance rifle with no modifications.

    Buffer System

    The Buffer Tube, machined from a single piece of 6061 aluminum, is one of the important features. It has a lip that extends into the receiver and provides support against carrier tilt (not as important since this is a direct impingement system). It has four drain holes to prevent hydrostatic locking of the reciprocating buffer, and is fluted to shed debris. It uses a standard carbine length H2 buffer and spring. The difference between this buffer and more commonly available ones is that the buffer itself is a tungsten weight housed in a steel body, coated in nickel Teflon. So it is both heavier and slicker.



    The tube uses a hex bolt to help align the tube to the lower receiver and two locking allen heads at the top to keep the buffer tube from rotating on the lower. If you are not familiar with the PWS buffer tube, what this boils down to is: No. More. Castle. Nut. On the Modern Musket this buffer tube also has a six-position stop, allowing for standard AR collapsible stocks to be attached.



    The bolt carrier group is PWS’s Enhanced Bolt Carrier. It is precision machined and isonite treated (just like the barrel). The bolt carrier has increased mass (it is significantly thicker than a standard BCG) which should both extend dwell time and slightly delay unlock. What this means is that it allows the chamber pressure to be reduced making extraction easier and thus accumulating less wear and tear on the system.


    There are a number of gaps and channels between skid pads on the BCG which provides fewer points of contact. With fewer points there should be less overall friction, and this should reduce the accumulation of residue and grime, as well as further reduce wear and tear.

    The action uses a low profile gas block that is machined in-house from heat-treated tool steel. It is also lighter than other low profile gas blocks. It looks to be almost half the length of most other ones I’ve encountered.

    The charging handle is the BCM Gunfighter, one I personally think is one of the better ones out there (feel free to troll or support that opinion in the comments below).

    The trigger is ALG Defense’s Quality Mil-Spec trigger, and was set somewhere around 6.5 lbs (if I had to guess).



    The included Lucid HD7 (a red dot sight) is stated to be waterproof, shock proof and fog proof. It also has four different reticles you can cycle through (which is gimmicky in my option; no offense to the CoD fans out there). It is also covered by a lifetime warranty.


    It does not come with any “iron sights” so if you want a sighting system that doesn’t need batteries, you will need to add it.


    The rail is mounted on the Primary Weapon System designed full-length free-floating hand guard (using the KeyMod system). The quad rail system is not proprietary and can be installed really on any AR platform. It is a modular quad rail; you can remove the rail without having to replace the entire component. The rail also had quick disconnect sling swivel mounts fore and aft.


    Installed were Magpul MOE buttstock, the Magpul trigger guard and Magpul pistol grip (with integral storage).



    The barrel is the Primary Weapons Systems’ “standard” Isonite QPQ treated and features a 1:8 twist. If you are not familiar with Isonite treatment, the tl;dr is that you take a barrel, give it a salt bath to nitrocarburize it (producing a layer of iron nitride), polish the hell out of it, and then give it a nice soak back in the salt bath after which you rinse it and oil it (which is eerily similar sounding to the pedicures my wife gets).

    Muzzle Device

    The muzzle device is the PWS Triad 556. It actually offers true flash suppression (compared to the CQB on the Diablo, though, what doesn’t?). It also really reduces muzzle rise. The other “hot” feature is that it is a suppressor compatible mount (for suppressors compatible with A2 flash hiders).



    I brought my wife and a couple of friends (including Thomas Gomez, another TFB writer), because shooting is always better in groups.

    For this shoot, I broke out some of my .223 stores and went through a little north of 600 rounds. Again, it was nice, dirty Russian surplus (though Thomas Gomez really wanted me to shoot some of his prissy Federal XM193)

    We shot from about 50 feet to 6 feet.

    I initially ran a couple of PMags through it to get a feel for how it shot, and following that we ran a whole bunch of magazines that Thomas brought (breakdown of that in the reliability section).

    Just like the Diablo, we ran the gun as fast as we could load the magazines, and it also eventually got too hot to hold without gloves.


    Thomas brought out a number of magazines for our shoot. It is definitely useful to try a bunch of different ones out as sometimes weapons are a bit finicky about what they accept due to manufacturing tolerance differences. In this case we used both Generation 1 (and Generation 3) 30 round Magpul PMags as well as a 20 round Generation 1. A current generation USGI magazine with the tan anti-tilt follower. A BCM GI Magazine without an anti-tilt follower. A Troy Battle Mag. And a crappy 20 round Thermold Magazine. We did have a couple of misfeeds from the Gen 1 PMag and the Troy magazine.

    As I mentioned before, I ran around 600 rounds of dirty Tula through it, and I did not clean, nor lubricate, the weapon once.


    Not once did I have a problem with feeding or round ejection with the .223 rounds despite shooting in a couple of awkward positions, and while on the move. We basically ran the same drills with the Modern Musket as we did with the Diablo. Thomas did have a malfunction with a couple rounds of XM193. Not entire sure why, though I’d like to claim that the rifle really likes the taste of the dirty Russian ammo and not the snooty Federal. I would like to also put out that the XM193 was somewhere around the 14th magazine of ammo.


    The Primary Weapons Systems Modern Musket is a well-built, solidly performing AR. PWS has thoughtfully assembled a rifle from a number of high-quality components and out of the box it is “range ready”.

    If you look at the rifle “big picture” what you will see is that the design and components are done in such a way as to really increase the longevity of the rifle. While you should still perform routine maintenance, the components themselves are set up to give you years of life. My biggest complaint (and the only one I can come up with) is that it doesn’t come with iron sights. I was impressed enough that I am adding one to my harem of rifles.

    Note: It is so well designed and the quality is such that Albuquerque Police Department recently contracted to get 350 units of this exact model to outfit qualified officers.


    • Potentially huge lifespan on barrel (Isonite QPQ)
    • “Range ready”
    • Solid optics
    • Beefy internal components
    • .223 Wylde
    • Direct Impingement Gas (if you like DI Gas Systems)


    • Direct Impingement Gas (if you hate DI Gas Systems)
    • No iron sights.


    • Model Number: DI-14/DI-16
    • Action Type: Semi-automatic
    • Caliber: .223 Wylde
    • Capacity: 30 rounds
    • Length: 31.4″/33″
    • Barrel Length: 14.5″/16″ Isonite QPQ Treated
    • Weight: 6lbs, 7oz/ 6lbs, 12oz
    • Sights: Lucid HD7
    • Price: Street ~$1499 (all variants)

    Tom is a former Navy Corpsman that spent some time bumbling around the deserts of Iraq with a Marine Recon unit, kicking in tent flaps and harassing sheep. Prior to that he was a paramedic somewhere in DFW, also doing some Executive Protection work between shifts. Now that those exciting days are behind him, he teaches wilderness medicine and runs an on-demand medical staffing business. He hopes that his posts will help you find solid gear that will survive whatever you can throw at it–he is known (in certain circles) for his curse…ahem, ability…to find the breaking point of anything.

    You can reach him at tom.r AT or at