USMC Request for Information on new Infantry Rifle, Suppressor, Optics; Army leadership looking for a heavier 7.62 option

In reverse order of the title, first up is the oncoming buzz about the Army looking to go back to a 7.62×51 solution to arm the Infantry:

With that in mind…The USMC has been pretty coy with the M27, and the RFI they put up earlier this month contains some interesting data.

You can read Nathaniel F’s thoughts on it here:

Here are some, not all, of the characteristics found in section 3 of the USMC RFI.

Required Characteristics

  • 14.5” barrel option, with 24,000 round life with AB49 – 2 MOA precision threshold, 1 MOA precision objective for majority of barrel life (Mean radius) (Army Capability Based Assessment requirements).
  • Bolt carrier group optimized for M855A1 use with Picatinny Durable Solid Lubricant coating or any similar variations thereof

Desired Characteristics

  • Ability to fire AB39, .264 USA, .260 Remington, M80A1, etc.
  • Modular bolt/barrel/magazine & magazine insert conversion packages for caliber changes (compatibility with A059, AB49, AB57, Mk255 Mod 0, etc) and optimized for respective caliber, charge, burn rate, and pressure curve (barrel threads can be 1/2X28 or 5/8X24)
  • Minimum mass cycling components to create no higher G-load than unsuppressed M110 SASS when fired
  • System deliberately built to perform at optimal level while suppressed – must divert gasses away from the shooter’s eye
  • Bolt and barrel life greater than 15,000 rounds with no more than 200 FPS velocity loss

So…I think that is all very interesting, and it may give us some clues as to where the USMC is looking to go into the future.

My thoughts, the USMC isn’t necessarily wedded to any cartridge for this RFI. Consider the following 5.56×45 rounds listed: AB49 is “Mk 318 Mod 0” 5.56×45.  AO59 is standard M855 green tip ball. AB57 is M855A1. Mk 255 Mod O is a “frangible” reduced penetration round designed for room clearing. Moving up is the non-standard ammo like .264 USA, 260 Rem. Moving up from that is the 7.62×51 standard ammo: AB39 is Mk 316 Mod 0, aka the Navy upgraded version of M118LR 7.62×51 sniper ammunition, M80A1 is of course the new 130gr steel tipped copper bullet.

What this MAY mean is that the USMC is willing to go Army standard on future ammunition with the M855A1 and M80A1.

The accuracy standards, 2 minutes over the course of the barrel life, with an objective barrel life of over 15,000 rounds, are definitely going to be tough to do. Even with cold hammer forged and double chrome lined barrels that is going to be a very, VERY hard thing to do. The only commercial rifle barrel that I know which is even advertised with a round count over 15k was the original FN SPR, which is a bolt action rifle. Remember that barrel life is mainly defined by heat, and semi autos heat up barrels much faster than bolt action rifles.

However, a stellite lined barrel may be what the USMC is really looking for. Notice the 15,000 round count number on the advertising for stellite lined M240 barrels here (showing a chamber wear guage through three barrels, hardly definitive proof but it illustrates a point):


Photo Copyright US Ordnance.

So there you have it, the USMC is looking for a modular rifle with a long lasting, accurate barrel. The minimal caliber is 5.56×45, max caliber is 7.62×51, and are open to options in between. They are clearly looking for a gas piston design based on the desire to divert gasses away from the shooters eyes when suppressed (rather than adopting a different suppressor technology).

So…what do I think this RFI is meant to find? Probably some version of a piston AR-10 that can shoot 5.56×45 with a magazine block adapter and stellite lined barrels for all calibers with an easy caliber swap by switching upper receivers and magazine block. The caliber selection and barrel life requirements open up the field to competitors, but the “desired characteristics” don’t mean a hill of beans in anything but a tie breaker between two systems that meet all the “required characteristics.”

So what is the RFI likely to find? An “M27A1” or even an M4A2 with a free float tube which has a stellite lined barrel, maybe a twist rate loosened to 1:7.5 or 1:7.7 to squeeze that last thousand rounds of useful accuracy out of the barrel.

Also included in the RFI, immediately following Section 3, is Section 4, Suppressor:

Infantry Rifle Suppressor The Marine Corps is interested in new and emerging suppressor technologies. The Marine Corps is interested in a rifle that is guided by the following specific requirements:

Required Characteristics

  •  Advanced venting to reduce back pressure, cyclic rate, and gas blowback
  • Gas flow improvements to reduce or eliminate first-round flash
  • Effective attenuation of noise and dust signatures – desired to be hearing safe
  • Minimal and consistent point-of-impact shift of no more than 1.5 MOA
  • Constructed of advanced high-temperature, corrosion resistant alloys with advanced coatings or treatments
  • Service life of 24,000 rounds firing AB49 through a 14.5” barrel
  • No longer than 6.5”, desired length 5” (overall length of suppressor), may fit over muzzle device
  • Must include locking capability (fast QA/QD capability desirable, but primarily intended to prevent unthreading of suppressor and inevitable baffle strikes)
  • May not weigh more than 20 oz.
  • Suppressor shall not be capable of disassembly at 1st echelon maintenance level (cleaning interval shall be recommended by manufacturer on basis of weight gain due to carbon buildup if any)
  • May include muzzle break/flash suppressor. If included, will utilize existing 1/2X28 threads. May use shims or washers to index properly. May require use of Rocksett to prevent unthreading during use. May not exceed 25 inch pounds of torque for installation. Signature reduction through mitigation of flash and blast overpressure (velocity of redirected gasses as well) is highly desirable.
  • Existing NSNs, safety certifications, use or testing by other military agencies is highly desirable

Things NOT specified by this include sound reduction or recoil reduction. But it looks like this part of the RFI was built to get OSS Suppressors into the game:


Image Copyright OSS Suppressors.

The no baffle construction of OSS suppressors took the gunternet by storm as lots of folks really hated the AR blowback on their suppressed black rifles. The open flow design of the OSS system means that carbon fouling is cleanable by a “dunk tank” solution as there are no parts that would hold solvent from draining out after cleaning although some baffled suppressors also have this feature so I wouldn’t count them out entirely.

Now If the suppressor RFI wasn’t built as it was, I would actually discount the M4 platform from consideration. But once you combine an M4 with a stellite lined barrel an an OSS suppressor, you can meet all the requirements for the Infantry Rifle portion in section 3 (I only included the the requirements that I wanted to talk about, you can read the whole list on FBO which Nathan F provided a link to).

So why is the M4 a contender? Well the military owns the technical data package now, which is something it doesn’t own for the M27. This means that modifications to suit the USMC are much simpler than modifying the M27 to suit the USMC, and cheaper too.

The last section, section 5, on Optics, makes it very clear that a 1-8×32 powered variable is what the USMC is looking for ideally. Specifically one that uses some sort of “projection” reticle so that at 1x magnification it can be used as a Red Dot scope for CQB.

Required Characteristics

  • Magnification from 0/1-8 power to PID threats (presence of weapon) out to 600M, and engage threats in close proximity
  • Must possess large and forgiving eyebox and extended eye relief
  • Included ambidextrous capable feature to rapidly adjust magnification with non firing hand
  • Reticle features for engaging moving threats out to 150M and rapid ranging feature that accounts for average width of human head and of shoulders
  • Compatible with clip-on current night vision or thrermal imaging devices (e.g PVS-24A, PAS-27, etc)
  • Low profile elevation turret or cap – turrets locking or capped to prevent inadvertent loss of zero in combat conditions
  • Scope base/rings must return to zero after removal
  • Center of reticle must have daylight bright illuminated dot for close quarter use at 0/1 power.
  • Must meet MIL-STD 810G environmental/durability requirements

Desired Characteristics

  • Scalable and modular to accept future digital feature set and new reticles Potential low end setting as red dot sight (RDS)
  • Form factor comparable to existing COTS optics with similar mid range magnification
  • Optimized for mounting height over rail at 1.54-1.93”
  • Battery life comparable to that of Aimpoint M4S CCO (Army standard optic).
  • Squad level networking and target designation capability
  • Visually displayed point of impact cue (drawing information from laser rangefinder and ballistic solvers, integral and/or external)

Currenty offerings on the market that sort of meet the RFI: Leupold 1-6×20 Mk6, Burris XTR 1-5×24, and Trijicon VCOG 1-6×24. I don’t think the USMC is going to get a product that has the squad level networking and target designation capability built into the optic, that’s the ultimate goal, is to enable someone who doesn’t have direct line of sight to be able to take the shot, but that’s a “system of systems” which requires some infrastructure not mentioned in the RFI.

The reason why I don’t think that Tracking Point is going to get much love here is twofold, battery life and networking security requirements in the age of “cyber” will make Tracking Point scopes overly complicated for this RFI. Seriously, the cyber security review requirements for spectrum dependent gear make it damn near impossible to get things fielded, let alone get authorization to use it in a foreign country even after the equipment has been uploaded to the Host Nation Spectrum Worldwide Database Online (HNSWDO, pronounced ‘Hans Widow’). The Burris Eliminator III series would serve as a good basis for a Burris offering, but I’m not sure if Burris wants to go down that route.

Specifically in the military there are pieces of kit that can designate a target and pass it off, things like an LRAS can do it, but these are big pieces of kit designed for artillery spotting. They require a high precision GPS fix, and a very accurate laser designater. I’m sure the technology CAN be miniaturized to fit on something the size of a rifle scope, but then you are back to the “networking” problem of cyber compliance review. To make it work there would have to be some interface with a tactical radio to get the information to other people, and while that CAN be done (it is done through digital fires nets all the time) it is currently a pretty bulky solution, and the computational requirements means that it can’t be done on a battery that lasts as long as an Aimpoint Comp M4 (think smartphone level of computer requirements, so recharging every day to few days necessary unless much bigger LION batteries are used). The USMC did just drop some cash on an Australian electronics control module company so that an Infantryman could control all electronics on their rifle from one point, so maybe the USMC is interested in creating that “network ecosystem” at some point.

But..if you had an M4, M27, or AR10 with stellite lined heavy barrel, free float quad rail, topped with a Trijicon VCOG and suppressed with an OSS helix, launching M855A1, you wouldn’t be outgunned by much on the battlefield. That combination would serve in CQB all the way out to precision shooting at 6oo meters, and do so with a much reduced signature (although thermally the weapon would heat up, no avoiding that just yet).

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