Dead Foot Arms MCS (Modified Cycle System)

The pursuit of short operating systems for AR-15s and their derivatives has been insanely fun to watch. Options keep getting shorter and shorter, especially with the latest offerings from Battle Arms Development, Maxim Defense, and others, all using a modified base buffer system.


Upstart Dead Foot Arms (whom I did have the pleasure of meeting at SHOTShow briefly) is now in the ring with their MCS, or “Modified Cycle System”. Unlike some of the other kits, it uses a modified bolt carrier (basically cutting off the tail just past the full-auto trip sear). From there, it adds a spring in a dual recoil spring system to cut down the total cycling receiver extension to just a few inches. Thus, the kit maintains full auto compatibility of which they report their dual recoil spring eliminates any bolt bounce in full auto weapons.


The kit is available directly from Dead Foot Arms, which includes a folding stock adapter compatible with existing buffer tubes (but one may want to use the an ultra compact LWRC kit for a sane length of pull). The Adapter allows the weapon to be fired while folded through use of an angled adapter dropping the stock beneath the ejection port.


Retail is pegged at $499 which includes the bolt, springs, buffer, and folding receiver extension assembly. First shipments are expected in May of 2016 per their website. The handgun only version (not folding adapter) is set at $375.

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Dickie

    Want & need

  • Ron

    Looks like the bolt carrier and buffer system used by the Carbon 15

    • Treadmarks

      Not quite. But close. Much shorter carrier in the carbon15 and only one spring.

  • Ambassador Vader

    You can shoot it with the stock folded to the side, but isn’t the stock in the way? Except for lefty shooters, but folding to the left might have been a smarter design.

    • Big Burd

      if you watch the video, when folded the stock is offset quite a bit from the reciever by the swingarm which is also apparent if you look at the picture with the individual components. Though if you have wide buttstocks with battery compartments and what-not you may have issues.

  • Daniel M. Ramos

    I wonder if you could somehow rig it for a stock that folded under the gun like Keltec did for the SU16C. That would be really sweet. Does it at least sound like a cool idea?

    • Mike C

      So we’ve gone from putting M4 stocks on AKs to putting side and underfolding stocks on ARs…
      The grass is always greener on the other side…

    • mechamaster

      Yes, I think it’s possible.

      Cool idea indeed for SBR rig.

  • iowaclass

    Query: Ares SCR with a ZM upper — possible?

  • Greg Anderson

    Will parts kits(springs, buffer, bolt carriers) be available at not-insane prices? I don’t mind proprietary stuff so long as getting replacements isn’t terrible.

    • Dead Foot Arms LLC

      Greg, thanks for your comment. Our system is guaranteed for life, anything needs replacement and we do it free of charge!

      • Greg Anderson

        DFA, thanks for your reply. It’s good to know that you guys have the confidence to back your product with that kind of guarantee, but having reasonably priced parts is important for two reasons:

        1) Appeal to those that run their kit hard, or think they run their kit hard. You know the guy. “The weak part of the AR-15 is the lugs! Always keep sixteen spare BCGs in your kit!” But then there are also 3gun guys who have spared themselves a long drive by having a spare BCG on hand. A spare never hurt anyone and covers a lot of bases. That last part is where I’m at – I’ve got no problems with a propreteary bolt carrier, but I’d like to keep an extra on hand just in case. Right now I’m running a Gibbz side charger, and you better believe I got a spare enhanced/extended cam pin on hand, because waiting a week or two sucks.

        2) Marketing to the guys who smile when the conversation turns to the end of the world. I’m sure DFA will be around for many years, but that’s of small comfort when the internet doesn’t work and all the package delivery drivers are being chased by zombies or whatever else we’re afraid of this week. A lot of these guys don’t like to use anything non-standardized if replacement is questionable.

        • steveday72

          Well explained Greg… I’d never modify any potentially life-saving equipment to be non-standard if I could not have spare parts for it on hand to immediately fix any problem.

  • Right-wing Realist✓ᴺᵃᵗᶦᵒᶰᵃˡᶦˢᵗ

    Can we just get an LR300 already?

    • mechamaster

      ( If I’m not mistaken ) the tool is needed to fieldstrip the Z&M LR300 spring and there is little washer that can easily lost if not careful.

  • Randy Graham

    On a side note: What is with all the gun companies today with stupid names like Dead Foot Arms? What happened to just naming the company after the founder like they did in the old days? Where are all the “Colts,” and “Remington’s” at today? Instead we get stupid sounding names that sound like the screen name of a thirteen year old playing Call Of Duty. Ninja Skull Arms. Viking Zombie Arms. BazookaFlash Arms. It’s embarrassing to own something with one of these silly names plastered all over it.

    • Dead Foot Arms LLC

      Dead Foot Arms is named after my Grandpa, a WWII and Korean War Vet who later in life lost his leg due to disease. His nickname from then on was Dead Foot. I proudly named my company after him. There’s your answer my friend!

  • Charles Newman

    Just love how you can’t get to the trigger when folded. Has no practical value except to save a little space in the safe. Get a Sig MCX. They got it right.

    • Kent Campbell

      Looks like you can reach it if you’re a lefty like me.

    • Dead Foot Arms LLC

      Trigger well is easily accessible with just about any stock on the market. We have dozens of pictures on our various pages which show that. The concept behind our system is based upon the idea that if you have an AR you like, you don’t have to drop $1850 for an MCX. Appreciate your opinion tho, thanks. We understand it’s not for everyone.