SOCOM Developing Caliber Conversion for SCAR

Officials with the Tampa-based USSOCOM followed up on our Mk-16 cancellation story with some clarifications about some of the data presented in the piece posted on

First off, the command took issue with my calling the program “cancelled.” Technically the SCAR program is still on, of course, but SOCOM has decided not to buy any more of the straight up 5.56 versions. OK…In my book that means the Mk-16 is cancelled, but I can see how they’d get some grief from some quarters about the legalistic terms.

Also, to be clear, SOCOM is not buying any additional Mk-17s than it was already planning to buy. If the article gave some folks that impression, that’s an incorrect read of the “buying more” bit. They’re buying more than they have now, and no more of the Mk-16s.

Another point. SOCOM said they are definitely having troopers turn in their Mk-16s when they redeploy and will not allow any Mk-16s in the inventory. What SOCOM is not clear on yet is what will happen to the roughly 850 SCAR-Ls once they’re back at the armory.

Now, there was confusion on the back and forth via email with SOCOM and FNH on this, but the command wanted to make sure we made this point clear. SOCOM will “complete development” of a kit that can convert the Mk-17 into a 5.56 if desired.

The original objective was to develop a single weapon capable of firing whatever caliber desired. That objective is met with the Mk 17 as the development of a conversion kit allows the operator to fire either 7.62mm or 5.56mm ammunition from the Mk 17. 

I did get my numbers mixed up on the original acquisition objective. What SOCOM followed up to me was that the JORD showed a requirement for 38,000 Mk-16s and 5,600 Mk-17s.

  • Joe

    god adopt the 6.5 and be done with this foolishness

  • frank

    They should have chosen the magpu. It already converts from 5.56 to 7.62 and back.

  • Bob

    What is with the .308 caliber mystique, the American Military has? First 30-40 Krag, 30-06 and then 7.62 Nato. Ballistically and every other way the 6.5 and 7mm have the 30 cal beat. Why does our military cling to 30 cal.? Lets go 6.5 and get it over with. Do something right for a change. We are talking war fighting here, not the best round to hunt deer or elk.

    • Riceball

      The issue has nothing to do with 5.56 vs 7.62, what it’s about is that SOCOM feels that the Mk 16 does not provide a significant improvement over the M4 or H&K 416 while costing more. What I’m taking away from this is that SOCOM will be issuing out M4 &/or 416s for their standard 5.56 rifle while sticking to the Mk 17 for 7.62 and not that they’re dropping 5.56 from their inventory in favor of 7.62 only.

  • IronV

    They were absolutely right to cancel it. Yes, it provides, by some measures, some slight but not statistically significant advantage over the M-4/M-16. But it’s like the optimal camo issue. How much time, energy, money and disruption do you put into a system that only provides incremental improvement over existing hardware? Not much i hope…

  • Rijoenpial

    Well, this is intriguing…Robinson’s XCR was at the time the best candidate with a modular system that could enable the conversion of the 5.56 to 7.62×39 just replacing the lower receiver, bolt and magazine… NOW, SOCOM dises the 5.56 weapon, prefers the 7.62×51 and is working on a conversion kit to turn the mk17 into an Mk16 if need be…

    This starts to sound like BIG budget cuts going on at USSOCOM level…yes, it sure does…
    What I don’t get is why they are so eager to remove the Mk16 out of armory… Are they planning on returning the ones they already have to FN and asking them for a refund?

    What a mess…

  • Cwolf88

    Takes years to develop a new reliable, effective round and millions of dollars.

    Have you ever seen a 6.5 or 6.8 20,000 rd full auto test? Nope.

    There are lots of considerations besides fps or foot-pounds. The Mk 318/Mk 319 are highly effective, even in short barrels.

    The Magpul Bushmaster ACR didn’t exist 7 years ago. Seven years of testing in the SCAR. The ACR still has not been tested.

  • Infidel4LIFE

    Iraq and a-stan are 2 different theatres. One was close up, this one here is mostly beyond 300 yds. I really would like to see the 6.8mm used, but we are going with wat we got. No more Mk16’s, but they are taking delivery of the SCAR-H. The Hk comes in 5.56 and 7.62? Thats where the $ is gonna be spent. I really never liked the 5.56, or the 9mm beretta.

  • JW417G

    The Robinson XCR is the best hybrid multi-caliber rifle on the market. Do the research and you’ll see for yourself. The SCAR can’t touch it…

    Rumor has it the XCR was dismissed from the SOCOM bidding / testing process because of “politics”. FN has been in bed with the military a long time…

  • FormerDirtDart

    Actually, the Robinson XCR was submitted for the SCAR competition. I don’t know about politics, but they were disqualified for failure to delivery the requested material with their weapons. They neglected to supply blank adapters. It seems petty, but it does show poor attention to detail by the company, which might suggest power quality control measures. Robinson used to have a portion of their website dedicated to bitching about their disqualification.

  • jmm

    The Robinson XCR didn’t exist when the SCAR competition took place in 2004, so it couldn’t have been dismissed “…because of politics.”

  • Unimpressed

    The Robinson gun was excluded from the competition because it was not delivered with all of the required components. Simple.

  • Joe

    These are all basically the same rifle that was designed in the 50’s as the M16. With some tweaks and slight improvements here and there. Time for a major new design, and for that to happen I suspect we will need to have a new bullet/cartridge. Probably caseless or a more powerful powder to make the rounds shorter in length. Until we get a breakthrough on ammo, the rifles will continue to look more and more like each other.

    Still with all that said I still hope for a new middle round 6.5, 6.8 or something…. :)

  • AndyB

    Maybe they’ll sell the Mk16s through the CMP ; )

  • Jim

    Since it only takes swaping of five parts to turn the Mk17 into a 5.56mm (or any other intermediary caliber)shooting rifle, it makes sense getting only one rifle instead of two. And NO, XCR, ACR or can’t shoot 7.62mm NATO.
    What sucks is that they’ll most likely revert to M4’s instead of using Mk17’s with conversion for the 5.56mm work. In SOCOM hands that M4 is chewing parts like crazy.

  • tony

    6.5 grendel has been tested and found to be superior to both 5.56 and 7.62 NATO. Just goes with that round and stop the nonsense.

  • NavCop315


    While math and science agree with you, NATO does not, and we will always go towards a NATO standard round, at least for mass use. We use the .338 Lapua for some long range stuff, but thats small amount purchases, we’ll stick with the 9MM/5.56/7.62 calibers for a long time now to maintain NATO compatibility, regardless of the performance of many clearly superior cartridges.

  • Daruli2004

    i guess it´s not just a matter of caliber, it´s a mater of realibility of the gun, under stress conditions, and the FN SCAR succeeded all competitors !! And i still wonder why still that fanatic love of the US military whit a 40 years old disign !!

  • Billy

    Uhhhmmm….. KitUp…. Is possible to make 6.5 NATO standard????????

  • Kurt

    I just love the discussion on calibers and new rifles. No matter what there issued why can’t the normal Joe deploy with a pistol? Or one privately purchased, like a Glock? AR pistol for mech boys? It seems killing can only be done “their” way or no way. What if your rifle goes down? Don’t even issue the bayonet. Fight with your hands, cause even grenades are to dangerous. How can anyone think war is dangerous? I think the Pentagon forgot what “fighting” means. In my oppinion, they don’t care about your life, just the way you are perceived in this kinder gentler service. Up close, shot placement is key. Far away caliber is king. Because of our rules of engagement we often ask our rifle to do many other jobs it is not really designed to do. America wastes money on military budget items that have nothing to do with producing and maintaining warriors, because its confused about what is important. So, one size must fit all will keep us chasing our tail. And never enough of what we need at the tip of the speer. Cold War Vet

  • john

    I think the army should adopt the acr & use the 6.5 grendel, but carry a 7.62×39 conversion kit in case they run out of ammo and have to pick it up from enemies. plus its ambi, reliable and modular.

  • john

    for the record though, i think western companies should look into BARS and make a sort of westernized AEK 971