DefendAR-15 AR-15 Bump Fire Stock

Fostech Outdoors are about to ship the DefendAR-15 bump fire stock for the AR-15. It is selling for $500.

It works just like the other bump fire stocks on the market: the rifle sits in the stock but is free to move backwards and forwards, the operator then pushes the rifle forward forcing the trigger against their trigger finger, the recoil of the fired round pushes the rifles back reseting the trigger, the operator’s continued forward pressure restarts the cycle. Repeat until out of ammunition.

[ Many thanks to jdun1911 for emailing me the link. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Samopal

    Oh yay, another grossly overpriced bumpfire stock. What makes this one $150 better than the SSAR?

    • RDW

      I think they are hoping the fact that it’s aluminum and not plastic will get them that extra dough. I would consider buying one for shits and giggles at about half that price…MAYBE….

  • chris

    I can’t see even $350 for a bump fire stock. Maybe they think they have to make all their money in a hurry in case uncle sugar pulls the plug.

    • JAFO

      I can’t see $25 for them, honestly. It’s worse than Magpul in the overpriced category.

      $350 or more, so that when some minor functionary at BATFE changes their mind, you, too, can be a felon without having actually broken the law.

      If you think the copy of the letter you have will save you- if you can find it… and if they admit they actually wrote it- you’re a fool.

      • JM

        Do you give up ALL of your rights so easily, or just your right to bear arms?

      • matt

        they’ve been around for over 20 years. when the atf got their panties in a bunch last time it was due to the spring in the stock, they sent letters to all the owners demanding they return the spring, everyone was allowed to keep their stocks which are essentially the same as the SFS stocks, made by the same guy too.

      • Paul Rain

        Oh yeah, great, then you can have paid $350 for a stock that doesn’t even have the gimmicky bumpfiring feature, but does have loose tolerances to allow you to engage in said bumpfiring. Great use of money.

      • jdun1911

        It’s almost half a year since the first bump fire stock went on sale. As far as I know no one got their door kick open and dog shot.

        The 1986 machine gun ban and NFA sooner or later will disappear. The 1986 machine gun ban is already in trouble.

        The 1986 ban was stuck down in federal court as illegal (U.S. v. Rock Island Armory, Inc. 1986 Machine gun act). The ATF did not appeal the ruling because it fear that the ruling will go beyond Illinois boarder.

        Than there is CATO Institute which has been aggressively trying to fully revive the privileges and immunities clause using the 2nd amendment. They where partially successful with the Mcdonald case. Everyone knows that privileges and immunities clause will come back. The courts just needs times to figure out the best way to do it.

    • matt

      not everyone is as broke as you

  • JAFO

    Yawn. Full auto is overrated. Unless you’re surpressing enemy troops during movement-to-contact or breaking contact, it’s a waste… and usually those times, too.

    • JM

      You can lock a bumpfire stock in place, so that it essentially becomes a fixed stock. More options is always better, in my opinion. You just never know.

    • matt

      not when you mount it to a saiga 12g with a 20 round drum.

    • Tom – UK

      “yawn” reading comment after comment saying full auto is overated is boring.

      You don’t have to buy it, you don’t have to use it

      but it sure as hell is fun if you do! ­čśÇ

    • Dan

      It’s difficult to imagine how automatic can be “overrated” when just about every fucking person in the military thinks it sucks. They’ll use it about two times, not be prepared, get knocked back by 5.56’s thunderous recoil, and then say it sucks and never try it again.

      Automatic is very useful, it’s just never trained for.

      • charles222


      • GunBug Bit

        Are you kidding? The 5.56’s thunderous recoil??

    • W

      i dont think its overrated, i just think its not as applicable as one would think it is as far as individual carbines go. automatics are useful for clearing out a trenchline or fighting position, though that is about as useful as it gets, even during a near or far ambush.

  • Ilgar De─čirmenci

    Question ; How legal these things there in America ?

    • JM

      100% legal

      • charles222

        100% legal with an asterisk. No way you’re even owning firearms, let alone this, if you’re a Lautenberg Amendment violator, or any kind of other felon, for that matter.

  • matt

    doesnt the slide fire stock guy have a bunch of patents?

  • PT

    Looks a lot nicer than the slide fire but the price is certainly a lot higher as well.

    Apparently the two companies are suing each other.

  • Bryan S.

    For that kind of cash, it should come with the lower.

  • Lance

    Just too bad its NOT adjustable and has a collapsible look to w/o the adjustments.

  • Jeff Smith

    Can anyone tell me how accurate these are compared to a normal, NFA registered M-16? Or can anyone tell me how accurate they are in general? I know that these aren’t meant for accurate shooting, but does the gun recoiling inside of the stock have a large effect on accuracy?

    I’ve never fired a full auto firearm, nor have I fired a bumpfire stock. But I would assume, using controlled bursts, you could keep most of your rounds on a human sized target at 100 yards using a standard M-16. Would this be possible with an AR-15 fitted with a bumpfire stock? Or does the design make it inherently inaccurate?

    • jdun1911

      Yes the gun recoiling inside of the stock will have a large effect on accuracy. However I’m not sure the hit ratio would be @100 yards on a human size target.

      I wouldn’t mind seeing the test result of the test if someone is willing to do it.

      • Jeff Smith

        jdun1911, Thanks!

  • Ben

    It’s great 2 see with the improving technologies that one day these devices will render the NFA standards academic as well as removing practical Class III distinctions.

  • David Cook

    I Saw this stock on Television,Gunsmoke, the gun store in Colorado. From what I saw, you couldn’t tell that it wasn’t fully Auto, and the owers wife and daughter who shot the rifle said they loved it and wanted them put on their personal A-rs. Even if it is completely legal, if caught with one on your gun, your going to jail and your gun seized. It’s guilty until proven inocent with things like that. I should know. I had a California Legal Limited edition Thompson from the American Historical Society. It was semi auto and puchased and registered in Calif but was seized when DOJ saw it. I was told it was to be destroyed due to a improper flash supressor. It now hangs on the wall over the Supervisers Desk in Redding Calif. I bought it as a memorial for my father for his service in the Pacific during WWII. How’s that for theft under color of authority. Son of a Bitches!

    • Samopal

      “Even if it is completely legal, if caught with one on your gun, your going to jail and your gun seized.”

      That’s ridiculous. Two manufacturers already make bumpfire stocks and thousands of people own and use them, many post videos online of the stocks in action. They’re sold at many major stores and ATF-approved. Nobody has had their gun seized and nobody has been thrown in jail.

      • Ben

        He might be writing about his local authorities in CA as it is a strange anti-gun state. They often have laws that duplicate federal laws and go beyond them when something appears that they don’t like.

      • Cymond

        Bumpfire stocks are illegal in California, along with Hellfire triggers and any other trigger activation speed enhancers.

        Also, there’s 2 ways to make a semi-auto rifle legal in California.

        Method 1: a fixed magazine allows you to have a pistol grip, folding/tele-stock, flash hider, threaded barrel, etc. ‘Fixed magazine’ is defined in the law as requiring a tool to remove, and the law states that a bullet IS considered a tool. Search for ‘AR-15 bullet button’ for more info.

        Method 2: removing all of the ‘scary’ features allows you to have removable magazines. For example, a standard Mini-14 doesn’t have a threaded barrel, pistol grip, or other banned features, so the Mini-14 can have removable mags. If someone puts a Mini-14 into a pistol-grip stock, then it needs a bullet-button just like an AR. As a note, flash hiders are restricted but compensator and muzzle brakes are unrestricted, Hybrid devices like the BattleComp and PWS-556 very popular in California because they are considered compensators even though they also offer some flash reduction. Also, I believe it is necessary to pin/weld a compensator to the rifle to avoid the rifle having a threaded barrel.

        If I were to guess, it sounds like David’s gun had removable magazines and a muzzle attachment that someone argued was a flash hider. It’s damn near impossible to get a straight answer out of the CA DOJ, and they’re even blatantly misrepresenting the law right on the DOJ website. They’ve been notified that the site is wrong but they won’t change it.

        • valorius

          Why dont you just move to america?

      • Cymond

        I need to correct myself.

        First, in CA, threaded barrels are restricted on handguns, but they’re not considered a restricted feature on a semi-auto rifle. When I realized that, I decided to go ‘featureless’ on my future AR build. I already plan on a fixed stock, so I just need to remove the pistol grip and flash hider. The Exile Machine Hammerhead is a good alternative to a pistolgrip.

        Second, CA DOJ has a procedure to determining whether or not a muzzle device is a flash hider. There is a VERY strong argument that hybrid devices like the Battlecomp & PWS 556FSC are considered flash hiders by the DOJ.

        My source:

        I will err on the side of caution until proven wrong.

      • Oyster

        Already on the books as illegal in CA.

    • Josh

      Son of a Bitches!

      Try, “Sons of bitches.”

      I would submit that whatever legal troubles you ran into probably had to do with your inability to effectively read and communicate in English.

      • David Cook

        Josh, thanks for the correction and the English lesson. I can see that you only like to read others comments so you can put your two cents in on how others express themselves. I never have been one to curse much but I thank you for the lesson. In California, the gun laws seem to change from day to day thanks to DOJ who make up their own laws when there is a nice firearm to be seized even if it’s completely legal. Do you actually read people’s comments for their content or do you just like to pick others comments apart to make yourself feel smart. Who really cares how it’s said. You make your case passionatley but civility is expected so please stay on the topic and respect the technical nature of others comments.

  • Mr.B

    So, for the price of a complete AR-15 rifle kit, I can buy a “stupid stock”. Cool!!!

  • charles222

    Fairly random class 3 question that this made me think of: If you paid the 200-buck stamp tax, bought a Giselle or other full-auto trigger group and dropped it into an AR you already own, would that be legal?

    • Jason

      Technically, yes it’s legal. Its effectively a DIAS (Drop in Auto SEAR), if you pay the tax stamp on the trigger group and SEAR as long as you don’t drop it into a non tax stamped SBR you are well within your legal rights. If however the tax stamp is for the full rifle as a whole or the lower and SEAR combo then you cannot modify it. Just make sure the tax stamp is for the SEAR and trigger group only, nothing else.


    • Cymond

      I think the question is ‘can someone file a Form-1 and make a full-auto’.

      No. All machine guns made after May 1986 can only be transfered to law enforcement agencies or the military. Private citizens cannot make full-autos or purchase any that were made after that date. ATF will deny a Form-1 to manufacture a machinegun. See the ‘Firearm Owners Protection Act’ of 1986 and the attached Hughes amendment.

      Jason is discussing the purchase of a sear/trigger group made and registered as a machine gun before the 1986 cut-off date. A similar example exists with Heckler & Koch longarms. There are registered H&K autosears that can be moved from one HK rifle to another. Hence, it’s possible to buy 1 autosear and use it in a MP5 clone, G3 clone, etc.

      As a note, it isn’t even possible to put a full-auto trigger system into a standard unmodified AR receiver. One would need to machine some material out of the receiver and drill an extra hole. It isn’t something that an average Joe can do at home with a dremel.

  • Rich

    If you have ever seen a person shoot a full auto for the first time, they always get a huge smile on their face and say that is so cool or similar words. Its fun as hell to rock and roll on a target. Now you can shell out $18,000 for an M-16 class III or spend $500 for your AR 15 and have just as much fun. Its legal if you can read they have the ATF head mans sign off right on their web site. You can print it out via PDF file and carry it with you if your panties are in a wedge.

  • jqc

    The first time some idiot goes on a shooting spree with one or shoots at the police with it they will be outlawed.

    • Samopal

      How? Under what law? Using what precedent? You know there’s a process to outlawing things, the government doesn’t just go “this is now illegal”.

    • Oyster

      Already outlawed in California

    • valorius

      That has already happened.

  • Ken

    This looks much better built than the Slide Fire. Only thing is the Slide Fire is easier to install with fewer parts. Hard to say which one is really better.

  • valorius

    The msrp of this unit and the one from slide fire is a complete and total rip off.