Searching for firearm patents online can be an interesting way to spend one’s time. It offers a deeper insight into known models and, sometimes, it offers some rather pleasant surprises. One of such events happened to a reader, who tipped us about a patent for a PDW-style firearm recently granted to inventor Caleb Crye, of Crye Precision fame.
Crye Precision @ TFB:
An MP7-Style PDW in 300 BLK? A Crye Patent Suggests So!
Crye PDW – The Brief
The patent US 11,105,574 B1, generically titled “Firearm”, covers a hypothetical “compact rifle-caliber firearm” conceived to provide advantages over current existing layouts.
As you can guess, the patent discloses solutions that would enable rifle caliber cartridges to be fed through the grip of the firearm. While the advantages of this configuration and the limitations that made it so far not viable may sound obvious to the TFB reader, the patent analyses them in-depth, and so shall we.
Crye PDW – ANALYSis of the current compact firearms
The document identifies three main configurations of automatic (or semi-automatic) repeating firearms, based on the location of the feeding assembly relative to the grip:
- Magazine in front of the grip;
- Magazine behind the grip (i.e. bullpup);
- Magazine through the grip.
With a focus on compact firearms, configurations 1 and 3 are shown as capable of employing collapsible or folding stocks. Although the patent does not mention any specific model, as we’ll see later we can consider the SIG MCX Rattler the benchmark for the “forward-fed” AR-style firearm. This weapon is relatively compact as it sacrifices barrel length to achieve this goal.
The bullpup reference as well is purely theoretical, however, since it is inferred it should be chambered in a full-sized rifle cartridge (5.56×45 NATO or bigger), and it may be fired one-handed, we like to think that the Bushmaster Arm-Pistol fits the bill. This layout is shown as capable of reducing overall length while preserving a suitably long barrel, to deliver the required ballistic performance.
The firearm fed through the grip is described as employing pistol caliber cartridges, offering the shortest layout (with stock folded/collapsed) together with the disadvantage of limited ballistics performance. We can think of the B&T MP9 to fit this role.
The analysis of the prior art concludes that, currently, having full-power rifle cartridges fed through the grip is not possible as the grip would end up being too large to allow comfortable operation of the firearm. Indeed, the closest attempt we can think of is the Russian AO-46 PDW prototype, which completely ditched the grip, replacing it with the magazine itself.
Crye PDW – TECHNICAL SOLUTIONS
The intent of the inventor is to solve the above-mentioned limitation, i.e. to offer a compact rifle-caliber firearm that can feed relatively long ammunition through a grip small enough to be handled by shooters other than André the Giant.
The document mentions “5.56×45 mm NATO , 7.62×39 mm , 7.62x51 mm NATO, 300 AAC Blackout, as well as other 6.5 mm variants, 0.50 variants, 0.300 variants, and 0.338 variants” as calibers of interest. The option of 7.62×51 mm may seem a bit excessive, with its 2.80″ overall length, while the wide range of AR-15-sized cartridges, 2.26″ overall, may be the main candidates of the development. The cross-sections of the loaded firearm depicted in the patent appear to show .300 BLK rounds.
The goal of feeding multiple cartridges through a grip of depth smaller than the cartridge length is achieved by the novel design through the concurrent influence of grip and magazine angles, follower angle, and ultimately cartridge angle. The rounds are meant to modify their orientation relative to the bore axis, in order to allow smooth feeding, once their reach the magazine lips. This may be achieved through the magazine shape and the presence of a two-piece follower, with its rearward part capable of pivoting up under spring pressure.
Quite a few trigonometry evaluations are involved and several potential angles are covered by the patent.
The document shows how this compact rifle-caliber firearm can be beneficial, in its hypothetical embodiments, both in terms of controllability and portability. The former is achieved through a center of balance closer to the shooter’s hand, compared to the other configurations. The portability is easily achieved as the firearm can be holstered not much differently than a common pistol.
The inventor does not disclose anything about the operating system, although the cross-sections show hints of a rotating-head bolt, likely gas-operated.
Crye PDW – Conclusions
We do not know if the solutions covered in this patent have already been tested in actual prototypes or they are just theoretical. Surely the details of some of the models used in the drawings suggest a fairly advanced stage of design.
As we all know, proper automatic feeding of a firearm is one of the biggest hurdles in firearm design, resulting in many new models employing proven magazines. This novel approach would definitely be bold, and, if truly functional, surely a breath of fresh air in the industry.
Would you love to have an MP7-style firearm chambered in .300 BLK or .223 Remington? We can only hope that the project is under development with a manufacturer and that we’ll soon see a suppressed version floating in the woods in Pete’s neighborhood.
All images from Patent US 11,105,574 B1 (United States Patent and Trademark Office), unless otherwise stated.