An Idea From A Reader

Annika, a reader of TFB, emailed me an idea for an AR-15 upper receiver and asked me if I could post it on the blog to see what y’all thought of it …

I’ve got a pretty straightforward idea that I’m hoping for some feedback
on. If you felt like making a post on this idea in order to get broader
feedback that would be cool, otherwise I’d just appreciate your own take
on it. If it seems like interest in the product would be high then this
could also serve as a petition to the industry in general to create such a

I want to suggest the creation of an inexpensive pistol-caliber AR upper
receiver with a right-side magazine well for accepting Glock mags (for
example). The ejector port could be positioned so as to eject spent cases
down through the lower receiver’s magazine well, and a simple
reciprocating charging handle could be positioned on the left side of the
receiver for manipulation using the supporting hand while maintaining a
standard grip, holding the firearm on target. Otherwise the arrangement
could be flipped so as to somewhat replicate the layout of the Sten.

This arrangement would have the obvious advantage of removing the lower
receiver from consideration when switching between different caliber upper
receivers. No dedicated lower receivers or annoying mag well blocks would
be required. This would also be a largely ambidextrous set-up, with
neutral downward ejection.

I imagine this would be targeted specifically towards shooter with a Slide
Fire Solutions SSAR-15 or other pump-fire stock wanting to shoot pistol
caliber ammunition but not wanting to have to deal with some of the
complication or expense you can currently expect with other compatible
pistol caliber carbines. This would be an entirely self-contained and
simple conversion unit.

In keeping with the overall intent to produce an inexpensive product I
imagine this receiver being constructed of glass reinforced Nylon (like
KelTec’s Zytel) or possibly with stamped sheet metal. If the LMT patent
could somehow be worked around it would be ideal for the handguard to
simply be an extension of the receiver, instead of a separate piece. I
imagine the receiver being manufactured with one top rail for optics and
no included iron-sights. Potentially the receiver could feature a
heavy-profile barrel of, say, 10″ with either the last 6″ milled out for
lighter weight or with a 6″ FH or shroud/extension permanently attached,
discouraging warping from heat generated by high-volume fire while
maintaining a low enough weight for maneuverability and effective use of a
bump-fire stock.

I have no interest in copyrighting, patenting or otherwise legally
claiming permanent ownership of this idea, since my primary interest would
be to see the product go into production in a timely fashion.

Included is a very rough sketch of how I imagine the final product could

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.


  • schizuki

    OK, there must be some very good reason why this hasn’t been done, because now it looks so obvious.

    I’d put the mag on the other side, but other than that, sign me up.

    • Nathan

      It would be too cool. That’s why it hasn’t ben done.

      The closest thing to that is the Prexis side feed 7.62×25 upper and the RogAR-15

      • Lolinski

        What if you somehow made it dual feed? The side would accept 7.62 tokarev while the standard magwell could be made to feed 7.62×39. I know it wouldnt be tactical but it would be interesting and fun. Or you could use 5.56 on the standard magwell while the side one is 5.7mm. The point would to use two calibers with one barrel without changing parts exept the magazine( obviously you cant have both mags in at once since the empty magwell would eject cases while the other one feeds)

  • Adam

    I want – I want

    I’ll take two

    1- 10mm glock compatible

    2 -7.62×25 ppsh compatible

  • Jesse tronier

    It’s called tokarev -_- not 7.62 ppsh

    • surplus-addict

      I think he means PPSH-41 magazine compatible. But the cheapest box magazines for 7.62×25 are the PPS-43 mags, which you can get for $100 for 10. So, either he’s an idiot, OT he named the wrong magazine.

    • he probably means ppsh magazine compatible since there is no suck thing as 10mm glock either.

      • David/Sharpie

        10 MM calibre Glock pistol magazine compatible, so yes there is a “suck” thing as that.

      • Metalhead2508

        No such thing huh?……

      • i was referring the a round called “10mm glock”

        “I want – I want

        I’ll take two

        1- 10mm glock compatible

        2 -7.62Γ—25 ppsh compatible”

        if any of you took the time to read or comprehend my sentence

      • David/Sharpie

        YOU took the comment wrong, don’t blame him because you misunderstood his comment.

        Like I said, he was talking about the Glock magazine, in 10 MM A calibre.

  • Jesse tronier

    that would be terrible, if you’re actually using it for CQC. You don’t what the mag to be there as it would get caught in the way, there is no were to grab aside from handguard (which is not always the right choice) You would not be able to stay on target when loading as easy.

    There is a reason the sten had very little service.

    • surplus-addict

      “There is a reason the sten had very little service.”

      Please, look at your history books again.

      They made MILLIONS upon MILLIONS of STEN’s! They were inexpensive, simple, rugged, and they worked. They were used by frontline troops. Rear guard troops, resistance fighters, you name it. And you say that they had very little service?!?!?!?

      • bbmg

        While the Sten has certainly seen a lot of service, that’s mostly because it was the only weapon available. Being used for want of anything else does not make it an ideal firearm.

      • W

        “While the Sten has certainly seen a lot of service, that’s mostly because it was the only weapon available”

        not true. lend lease thompsons were also available.

        availability is a red herring argument.

      • Chase

        “lend lease thompsons were also available.”

        They may have been available, but they were heavy, harder to make, and expensive.

      • W

        chase, my point was that the sten wasnt the only thing available. certainly not the only thing available in commonwealth arsenals outside of great britain.

      • Geodkyt

        And the Brits replaced the Sten with. . . ?

        The Sterling, which ALSO has a side mounted magazine. Issued Sterlings in front line service, too, right up until they finally retired the L1A1 (“inch” pattern FAL) from front-line service. . . SAS went to MP5s for counterterrorism use primarily because of the closed bolt accuracy (although the MP5 DOES lash up nicely when playing Spiderman outside a hostile embassy. . . πŸ™‚ )

        This is despite the fact that Britain ALSO tested telescoping bolt, feed through the grip, SMGs that led to the Vz23 and Uzi. They looked at conventional layout SMGs like the “Swedish K”, M3, and various German SMGs at roughly the same time.

        The side mounted magazine has two HUGE advantages:

        1. You’re not fighting gravity while feeding. Pretty much a nonissue these days, given better spring metallurgy, but it was still on their mind in 1945.

        2. (REALLY IMPORTANT) You can get really intimate with Mother Earth when you don’t have a long box mag sticking out the bottom. (The Australians took this to extremes, with their top mounted mag SMGs.)

    • around 40 countries used the Sten genius… including the US. 4 million were produced… little service my ass

    • schizuki

      Yes, the left-hand side feed is such a hindrance that the British copied the side-feeding MP28 as the Lanchester. Then replaced the Lanchester with the side-feeding Sten. Then replaced the Sten with the side-feeding Sterling.

  • Made to Beretta 92fs magazine compatible and I would Love to buy.

  • Jesse tronier

    There would mostly likely have feeding problems, were down the magazine catch. It would be 0% practical, interesting, but not practical at all.

  • BenJamin

    I’ve always wondered that myself. But instead of doing a pistol caliber side feed upper, why not a 12 gauge box mag side feed upper?

  • surplus-addict

    Reverse what side the mag is on, first thing. Also, just make it like a STEN but with the AR lower as the FCG and grip on the original STEN. A simple square thbe upper with a no-brainer bolt and a 16.25″ barrel would be dead simple, people have been doing it for YEARS. With a cheap polymer lower ($120), I could buy a Soumi M31 parts kit ($99) and some square 4140 steel tubing ($30), make a simple trunnion ($15) and with some creative drilling and riveting, I’d have an upper.

  • zbaer

    I’ve thought about a side mounted feed for a .308 or larger caliber, basically a scaled down version of the .50cal mag fed uppers that are out there.

    The interesting aspect with doing it in pistol caliber would be pushing the bolt face as far to the rear as possible to reduce overall length while keeping the 16in barrel. You might be able to get it 5 or 6 inches shorter than a regular AR if you do it right.

  • Dira

    I like it. Not just another AR-15.

  • C. Baker

    This seems like something you could approach the dudes at Red Jacket on Tv to make. I think it would be right up their alley and could be their next “game changer” πŸ˜‰

  • John Doe

    A cheap modern Sten gun would be awfully fun

  • Gidge

    A modern Sten would be an interesting toy. Some inspiration should be taken from the rare AUSTEN

  • Annika

    Sounds like folks would prefer a left side magazine position like the Sten? My thinking was that an extended mag on the left might be awkward to work around when using a bump-fire stock, depending on your support hand grip position, but perhaps this wouldn’t be much of an issue after all. Plus that would probably decrease mag swap time and reaching around to the right side for the charging handle wouldn’t take much effort.

    To zbaer, I agree, going for OAL reduction could also be a good goal.

    As for caliber choices, I’d push for starting with a standard 9mm for basic bump-fire plinking (judging from the success of the SSAR15 stock this would probably be popular), and if that did well enough then all sorts of calibers could be played with.

    Sub-$300 would be an ideal price. Much more than that and it might not be worth it from the consumer’s standpoint.

    • tincankilla

      @annika If this does go into production or a near-final design, I suggest you patent/copyright the design and open source it. That is, to keep someone else from claiming it as their own.

      • Annika

        Just about everything I’ve read has indicated to me that there’s almost no point to trying to patent a design if you don’t plan on making use of a patent lawyer, something I’m not in a position to do right now. Have your experiences been different?

    • Gidge

      If you’re ejecting downwards you could potentially design it to be user changeable between left and right hand side mag well. IT’d be a big deal for left handed shooters

      • Annika

        Unfortunately the complication level necessitated by this kind of modularity would probably drive the price up. I doubt the design could go anywhere as anything other than an inexpensive plinker. I could be wrong.

  • Phil

    I’m all for Glock mag compatibility and the side mounted charging handle, however I’m just not sure having the mag well on the side is a good idea. Seems easier to have it in its normal spot, but then again, it is appealing to not have to change the lower to change calibers. Definitely an interesting idea.

  • milo

    you know i have a couple cad designs similar to it, one is a bullpup ar-15 another is a side loader, the fun part is designing the internals

    • Risky

      Not trying to crap on anyone’s idea or anything… but simply being realistic, a sketch and an idea about some type of new firearm is completely pointless without any semi-serious plans to put it into production. No manufacturer, big or small, is ever going to pick it up based solely on a description or the concept that it’s a ‘good idea’. The only bigger waste of time would be arguing about the specifics of a nonexistent design…

      • Annika

        Well, not to sound too idealistic, but the firearm industry needs to learn how to respond more directly to consumer demand. If there’s no real demand for this then it’s no big deal if it doesn’t get picked up based solely on a simple design concept. If there is demand then the industry needs to learn that crowd-sourcing is in a real sense the product design/refining process of the future, and someone should take note.

      • milo

        well actually i landed in a contract for one of my less lethal designs, a little bit of imagination and a good amount o’ knowledge goes quite some ways. anyways this lady has a good idea and id be willing to work with her.

  • tincankilla

    Like the idea of using the lower’s mag well for ejection, as it opens up the geometry. Example: I’d put the mag on the left side, so it could be used as a grip by us righties. Then with a rail on the right side, the operator could rotate the weapon to switch from an optic on top to iron sights on the right.

  • Wes

    Maybe some aspects of the mechtec conversion could be borrowed.

  • Joe

    There is already a company in CA developing this exact thing. Can’t say who but wait a few months to see.

    • Annika

      Well that’s great then! Any idea what the general price range might be?

  • MightyGrey

    Checking a clear-chamber/round chambered may be a little difficult and potentially unsafe. Apart from that the free-fall mag may be the only other draw-back. Nice idea though!

    • Ian

      There’s no reason there can’t be a window opposite of the magazine. There is also no reason it couldn’t eject across the magazine, like the Sten and Sterling.

      It’s not intended to be a tacticool/tier one operator gun so free-fall magazines probably aren’t a huge concern. The author’s intent appears to be something cheap and fun to make noise with, like the vast majority of civilian owned firearms.

    • Geodkyt

      This sounds like the original intent is simply “a fun shooter”. As such, being able to casually eject magazines one handed is not a mission critical function. I’ve done quite well with my 10/22, despite not yet having fitted one of the one handed magazine levers (although I did mount an extended lever years ago, because the factory button sucked). . .

      Even so, most “tactical” (i.e., “military”) longarms in history take two hands to remove the magazine (AK47, M14, Sten, Sterling, FAL, M3 Grease Gun, Uzi, PPS43, PPSh41, Suomi, MP40, etc.), so this gun would not be at any disadavantage even if used as a “tactical” weapon. Once your hand is already at the magwell to hit the release, it is no trouble to flick the mag free and let it fall on the ground if you are in a hurry.

      Until recently, the standard magazine release location for any semiauto pistol not US designed was the “heel” location, which necessitated two hands. Some pistols (even after the rest of the world came back to the “US” style push button behind the trigger) were specifcally designed so their magazines DIDN’T fall free (early Glocks, before American police agencies complained loudly enough).

      The reason? Too many German Leutnants (and other troops armed with the P08 Luger, which had an “American” style push button mag release) found themselves at the enemy trenchline, only to realize they were all out of magazines — having ejected their empties to “fall free” into the mud of No Man’s Land. That’s why the successor to the P08 was the P38 — which had a heel mag release, forcing you to use two hands so you could catch the empty mag. European armies noted Imperial Germany’s problem and solution, and by and large followed suit (those that didn’t were generally using Browning design pistols, or rip-offs of Browning pistols). Even with good logistics, there’s a limit to how many thousand replacement mags they can move to the front, in addition to everything else the troops need. πŸ˜‰

      I’ve done speedy reloads on Sten and Sterling MGs, and never noticed a serious problem with having to use two hands AND not having gravity able to drag the mag clear because it’s horizontal. Neither did the British or British Commonwealth militaries when they issued the Sten and Sterling.

      I’d say it’s a non-issue, except for people who are only really familiar with the AR15 and US style pistols and “the Modern Technique”, or who plan to use this for IPSC-style shooting.

  • Mr.B

    It might not be the most practical and efficient design for high-speed low drag applications, but to have fun and to play around with something that will go “bang” and use mags that most of us already own, this thing is a great idea

  • Joseph

    Why not just fashion the upper to already have a magwell that inserts into the lower? The CM901 kind of does that (except it’s not all one piece), but with a pistol caliber upper the flexibility is somewhat more accommodating. The somewhat annoying magwell block would sort of not be annoying anymore.

    • Annika

      Sure, that might work, although working out the magazine release could be tricky in that confined space. For absolute simplicity I figured the side magazine well would be just that much easier to produce, but that might not be. Ejection would of course then not be ambi, unless it had some sort of modular ejection ports, which would again cut the simplicity and probably increase cost.

    • Hking

      You would be limited with what mags you can use. I think the idea is to use high capacity modern mags like glock or even MP5 mags, instead of UZI or sten mags.

    • tom tom

      Exactly what I was thinking. Since its a smaller mag (cross section) you would be able to fit through the existing mag well. I am thinking a Glock 33rd would go nicely.

  • Ed

    I have had the exact same thought for making a .308 upper that fits standard lowers. For a .308 possibly load the mag from the left side and eject out the right (ala FG-42) since I’m not sure if .308 casing will drop through an AR magwell without clogging?

    • gunsandrockets

      For a rifle caliber AR-15 upper I’ve thought that the idea of a top feed bottom eject design similar to a BREN configuration would work well. Not only would it be fully ambidextrous it could use extra long magazines available from military surplus without bottoming out the AR-15 when in the prone position.

  • Nathaniel

    It’s a neat idea, but my primary objection to pistol caliber carbines is that they’re pistol caliber but rifle size.

    Being effectively full auto would help, though. I still think I’d rather have an AR-15 than a Neosten, though.

    Feel free to use “Neosten”, BTW.

    • noob

      Chamber it in 10mm auto and you have something like .44 magnum kinetic energy.

      I recall a lot of rifles in .44 magnum.

  • BillyBones

    Impractical for the outlay in capital.
    I don’t see any benefit and all detractions from modifying the upper to accommodate a pistol caliber, side magazine fed rifle.

  • bbmg
  • Tony

    It should feed from the left hand side so that magazines can be easily changed by a right handed operator.

    • Annika

      Yeah the general consensus seems to be left side magazine, not right. That makes sense. Either that or an ambidextrous/modular magazine well arrangement, which would probably drive cost up significantly.

      • Geodkyt

        There’s a reason most side mounted magazine weapons have been left side mags. Even guns that started out as right side magazine guns. In short, 90% of the world is right handed. Later Bergman SMGs, Stens, Sterlings, FG42, a variety of LMGs, etc., — all worked just fine with left side feed ONLY.

        Designing a reversible system would add a LOT of cost for 10% of the shooting community. And super-modularity at the level of “any end user who can clean it can play Tinker Toy with the configuration” level, is the weapons system killer. TANSTAAFL means that LMG/SMG/AR/DMR/coax MG designs end up too bulky, too expensive, too finicky, too easy to screw up (which the DESIGNER will get blamed for, not the Cletus who fiddled with stuff he doesn’t understand and put it together wrong), and/or often times such a compromise of varying ideals that it doesn’t do anything really well. *

        On the other hand, a system that used a straight through side to side feed system, ignoring the AR magwell altogether, could be made fairly readily reversible, even in rifle cailbers with piston or DI gas systems:

        1. Make magwell detatchable by the end user, even if it’s an “in the shop with basic tools” kinda deal. (In fact, it would be ADVANTAGEOUS to design it so that swapping the magwell over is not complex nore require odd tools, but IS more of a PITA than normal stripping and more like setting up your AR15 with a particular stock and pistol grip setup. You’ll see why a little later on. . . )

        2. Make the magwell mating surfaces symmetrical, top & bottom (bonus points for NOT making it symmetrical fore and aft, so fumble fingered idiots don’t install it backwards).

        3. Use the same pattern magwell/ejection port on each side, including magwell attachment surfaces. Voila! Feeding is amibidextrous (with tools).

        4. Make the bolt so it functions whether you install it right side up (left hand feed, right hand eject) or upside down (right feed, left eject).

        The only problem is that it will still be relatively easy to get the bolt in upside down without realizing it, which would have your extractor and ejector trying to throw cases back into the magazine. . .

        If you went with a design where the magwell was ambi, but the user had to use the appropriate bolt for the desired feed direction, you could keep the idea of using the AR15 magwell as the ejection port (which is a really cool idea, BTW, for more reasons than just “the brass all ends up between your feet for collection”). In this case, making the magwell swap so that it is a 10 minute job with a Allen screwdriver and some Loctite is a bonus, because there is less chance your user will inadvertently mount the magwell on the wrong side for his bolt during normal cleaning

        * Cue Stoner 63 history — the guys who used them in combat tended to use ONE configuration (generally as a belt-fed LMG) and leave it that way, and post-1986 reboots and revisions by Ares and Knight as the Stoner 86 and Stoner 96 were VASTLY improved by dumping modularity altogether in favor of a simplified, more rugged and reliable, LMG-only configuration.

  • bbmg

    I would much rather see one of these uppers adapted to a pistol caliber:

    The result would be slimmer and potentially of much higher capacity.

  • Jeff

    A lot of ideas for AR-15s coming out: bolt action 50 cal uppers, bull pup ARs, AR-57, .410 uppers, 12 gauge uppers even and now sten-type carbines

    Maybe someone should make a rifle version of the Sig p250 (doesn’t have to be DAO) and just have a drop in fire control unit which constitutes the firearm and have a modular system around it.

    • Frank

      It made me think of the AR-57 as well. The concepts are similar:
      Have your own interface to the magazine on the upper, use the original magazine well to eject casings.
      You can also use modified magazines to catch the spent casings.

    • Zermoid

      This isn’t a bad idea, the crossbow upper, now that was a bad idea!

      • gunslinger

        you mean the TAC-15?

        yeah…1300 for a crossbow “upper” (no lower parts, no optics) not so much. You can get a decent standard crossbow for that price.

    • Geodkyt

      MGI Modular magazine well system is the closest I’ve seen. The whole magwell assembly slides up and off the lower after you seperate the halves. Add the appropriate magwell and upper (or just barrel, if you have a quick change setup, which MGI also makes), and you’ve got a whole new claiber AR, that uses the “traditional” magazine for that caliber.

      MGI base receiver – $99. Magwell assembly ALONE – $275. Base receiver with magwell – $374. Full caliber kit (barrel & magwell, no upper or base lower) – $549. MGI quick change barrel upper – $599. Special bolt carrier for 7.62x39mm AK mag version – $125. Heck, a complete rifle from this system in just ONE caliber is $1300.

      THIS idea of leaving the lower untouched, and swapping the upper assembly, and should be much less expensive.

  • Ray

    So STEN meets AR-15 and uses a magazine that isn’t shitty? Sounds quite awesome if I am quite honest, I’d also love to see a STEN with an updated magazine well to accept Glock mags and anything else with a capacity of +20.

  • Fitz19d

    All the better with the new 50 round Glock Drum coming…..

    Just like a Borderlands 2 Pirate pistol for you gamers. aha.

  • gunslinger

    i’ve wondered myself why the ar wasn’t adapted to have a Sten upper.

    if it’s sub 300, then count me in. with the change to mag location (left side) and all.

    lets hope this gets some more traction.

    • Zermoid

      Guess I’m not the only one who thought the sketch looked alot like a sten gun……

  • I’m always in favor of borderlands gun ideas becoming a reality πŸ™‚

    If someone finds a way to make a working Mass Effect M-8 Avenger, I’d be excited about that too.

  • alannon

    I like the idea. I think the magazine location will get flack regardless of side, due to different shooting styles (and handedness).

    I do wonder how hard it would be to make the guts reversible (maybe symmetric, with feed based on mag location?), so by simply applying a different body it can handle either side.

    My only other suggestion would be a nonreciprocating bolt catch. They’re not that hard to engineer, and having the bolt flying about as you shoot can be problematic. πŸ˜‰

    • Ian

      A pistol bolt only recoils around an inch (under the assumption that this is a straight blowback, as Annika hasn’t specified). If the charging handle isn’t right in your face, it can be placed in a convenient to access, yet safe position pretty easily.

  • Ian

    Afaik LMT’s patent regarding their upper receiver only covers the method of attaching the barrel into said upper.

  • denny

    It’s good to see frank and un-profiteering manner the person is open to discuss his ideas with. However, with some experience in marketing design ideas behind my belt, I’d offer this advice:

    1. go to patent lawyer ASAP (lots of people see this and not all are necessarily respectfull to your intellectual property) and register this at least as “patent pending”.

    2. if you live in States, set up your bussines and do it yourself; that’s most viable way

    3. if you do not live in U.S., more there as did many others (e.g.founder of KEL-TECH ect.); that’s the best place for firearms I know of.

    4. this idea expands on versatility of AR system and guessing by reactions it will be positively received. Good luck to you!

    • denny

      Sorry for typos; it would be of use, if we had spell-check available when writing contributions. Thanx

      • Annika

        Again, she, not he. Right now I’m not in any position to pay for the services of a patent lawyer (if you know any patent lawyers who will do pro bono work then send them my way). With this design I don’t really care what happens to it, I just want to see something that at least accomplishes the same goal get produced. I have other design ideas that I will wait to get patented.

      • denny

        You have noble intents Annika (and sorry for slip about gender; it’s hard to guess from nicks). When I worked in States, things were done with local legal firm, company paid of course. Personally, I spent time ago couple of hours with patent lawyer and could not believe the bill, when it arrived, so I am leery to do it again. However, I know from people who patented their work (not in small arms field) that “patent pending” does not cost much (since it does not include serch, registration and future defence) and gives some sort of limited protection. Full suit procedure is certaily lot more costly and one has to judge it against perceived benefits. My approach is, when I am offering a design, to transfer patent rights onto interested party in lieu of reimbursment.

  • Let me share my ideas on further development of the idea. I apologize to those readers whose ideas I may repeat, because I haven’t read all the comments of this post.

    So here are my ideas:

    1. Imagine a stripped AR15 magazine body (no spring, no follower, no bottom plate … just the hollow body) inserted into the magwell ! It will make a kind of a tunnel for ejected cases to travel down through. What can it be useful for? Possibly for helicopter shooters to guide the spent cases straight down and avoid from having an ejected case … somewhere not desired to πŸ™‚

    2. Imagine that instead of a pistol magwell you have a an AK47 magwell !!! So the gun will be gas operated and have AR15 style charging handle. Operators can use it as an AR15, having the AK side-magwell as an ejection port. In case if you need to use AK mags and ammo you need to change the bolt (to fit the cartridge head and change the ejection direction ) and the barrel, which obviously is preferred to be a quick change one. Now you can insert AK mags from the side and eject the cases to bottom. Besides, AK magwell, or better to say the mag catch and the hook are not bulky and will stick out of profile of the AR15 not far than the forward assist. Also AK mag release assembly can do the AR15 cartridge deflector job, when shooting as an AR15 with STANAG mags. To me, it’s another level of modularity !

    Thank you for your attention. Any comments will be appreciated.

    P.S. Unfortunately many people like myself don’t have chance to live in USA and to enjoy the gun community and the freedoms that Second Amendment gives you. I have several such ideas on my own and they could worth to be made and who knows maybe could succeed.

    • anon

      You wouldn’t need a guide for the empties: A Mesh bag with an elasticized mouth could just be slipped over the funnel of the mag well. All the empties could be easily collected.

  • SKSlover

    lol at the slidefire stock he drew on it.

    • Annika

      She. And it was a very rough, quick sketch

      • noob

        My hat’s off to you ma’m. This upper kicks ass.

    • Ian

      Better sketch work than I can do and I actually design firearm bits.

  • Gabe

    If you could get it up to Canada and past the filthy mitts of the RCMP (who basically act as our ATF) then I’d pay up to $600-700 for one (prices of firearms are inflated here, to any American readers who might not know. New Glocks run $700ish for a 4th gen, and ARs are almost all 1k+)
    Being a lefty I would appreciate a reversible option, but to be honest I’d probably get one even if there wasn’t. Also, using pistol magazines here allows us to shoot 10 rounds from a semi-auto rather than 5, and if it accepted .40 mags we could legally cram 12ish rounds of 9mm in there (our laws have zero consistency. Hunting with an MG34? Golden. Hunting with an AR or handgun? Nope.)

    • David/Sharpie

      My Glock (Gen4) was $758 +/- after tax.

      Norc ARs run around $650-700 depending on where you go.

      I have a .40 Glock mag, it is HARDER to put 10 rounds of 9 in the .40 mag, 12? Yeah right, I think a double stack mag would work for that.

      I would love to be able to go outside a range with a handgun.

  • Eric

    Great idea. I say keep them coming. I appreciate being selfless and not even wanting a patent. Firearms are an industry and in any industry you have options. If you don’t want one you don’t have to buy it but ideas build industry, this idea could lead to other ideas. I love to train and have serious weapon time but i also love to plink and have fun. I think most people want to enjoy their range time. If you want to have your serious man toy “this could go to war” rifle than that’s fine, hide this upper in your closet so your other overly manly never deployed friends don’t see it. Ideas grow industry.

  • Brandon

    Build it, and they will come….

  • Geodkyt

    Great idea, for common pistol mag types (and Glock mags are pretty darned common)! Although I like the idea of using a fairly common SMG mag at some point, that’ll have be whole different uppers, to keep the price point down.

    I think the idea of a “chamber window” (i.e., a cutout where the ejection port would be in a conventional design, only you don’t eject through it — could even be smaller, say 10x20mm) to facilate verifying the gun is clear is a smart idea.

    There is no real reason why the standard charging handle couldn’t be used, and that will save some bucks in design and production. PLENTY of room behind teh mag to grab teh charging handle, even if you use teh modern technique of hooking one side only with your left hand. OTOH, using a handle farther forward pretty much limits you to proprietary handguards or float tubes, and will cost you more in development and production. (Personally, I’d prefer to stick with the standard charging handle and be able to use any handguards I like. You could ALSO market an accessory kit to install a non-recip forward handle on a proprietary handguard to those guys who want to charge it like an MP5. More options for your customers, more bucks for the manufacturer, EVERYONE’S happier.)

    I like the idea of a 7.62x39mm left-side feed (via real AK mags, not mutant AR mags) upper ejecting through the magwell.

    Likewise the same sort of setup for 7.62x25mm Tokarev (yeah, I recommend PPS43 mags as well) and 5.45x39mm uppers.

    All of these Russkie rounds will eject (even unfired rounds) merrily through the old AR mag well.

    To go with 7.62x51mm upper, yeah, you’re gonna have to do a Sten/Sterling/FG42/most belt fed GPMG/etc. style feed path from left through right. Don’t forget you probably won’t want to use your standard AR15 carbine buffer & spring, so the upper kit should include the proper buffer group that will work in an AR15 buffer tube. . .

    But it would be cool to stuff G3 or FAL mags in, WITHOUT having to build a whole AR10 lower with a Gissele trigger when I already have an AR15 lower with a Gissele trigger I love. Those SSA trigger groups ain’t exactly cheap. {grin}

    A .45ACP upper using M3 mags or Glock mags wouldn’t be a problem, and could be integrally suppressed. Pure sex, baby.

    • schizuki

      With pistol rounds, you can use cheap and simple blowback. That’s the charm of this. You start getting into rifle rounds and now you’re talking more complex design work.

      • Geodkyt

        True — but I wouldn’t expect the “locked breech” caliber versions anywhere NEAR the same price point as the unlocked blowback versions.

        Even at $600 – $700 per complete upper kit, a locked breech upper that I could use with a standard lower AND the “standard” milsurp mags for that caliber would be worth it. Look at the pricing on the AR lower variants that use non-AR15 milsurp mags.

        OTOH, I think $250 – $400 is a solid price target for an unlocked pistol caliber version, trending towards the lower end of that.

    • noob

      some Russian MGs feed right to left, but that’s okay. Lefty magwells for some uppers, righty magwells for others!

      While we’re talking caliber, PLEASE 10mm auto or .45ACP so we can rebarrel for .400 corbon (and maybe .400 corbon might become worthwhile).

      • Geodkyt

        True about most Russian GPMG designs (all both of them*) feeding from right to left.

        Most GPMGs (or even belt fed MGs in general) aren’t Russian. ;P

        (* RP46 and the PK series, that’s it for production Russian or Soviet GPMGs. Even if you include ALL Russian or Soviet belt fed MGs, it’s still only half a dozen or so. . .)

  • schizuki

    Put a full-length perforated barrel jacket on mine. I want a Neosterling.

    • Geodkyt

      If it’s set up so the front end of the upper is like a standard upper and barrel nut, you could take any float tube that looks cool to you, and mount that. Such as a smooth round tube with vent holes, no rails.

      Meanwhile, someone who wants more rails than the Chesapeake & Pacific line can do that.

      All without having to reinvent the wheel for each type of customer. Just offer two versions of each caliber/mag style — one WITH whatever tube the manufacturer uses as standard, one at a slight discount without ANY tube, so teh customer can mount whatever they like.

      MOAR options without increasing production cost = MOAR customer satisfaction = MOAR sales = MOAR profit. {grin}

  • Mike Knox

    I’m not sure if someone came up with this before. A lot of people have done Sten type upper AR15 garage guns before..

  • Tyson Chandler

    DO IT…this is a great idea!

  • Cymond

    Currently, budget-grade 5.56 uppers (like Del-Ton) cost around $400 for a complete upper (including charging handle and bolt carrier group).

    The cheapest complete 9mm upper I can find is $500 (RRA), and doesn’t include a magwell adapter block (another $150 give or take).

    I would be thrilled to have a complete 9mm conversion for sub-$400, and at sub-$300 they’ll sell like hotcakes as long as they’re reasonably reliable.

    The key to this product is price. If you can produce them and keep the price down, then you really have something. If the price rises too high, then what’s the point?

    Consider that a side-mounted magazine allows for other calibers, such as 7.62×25 and .45 ACP

    Also consider a tubular steel receiver like a sten, sterling, etc. Take a look at the book ‘Home Workshop Guns Volume 5’ for a starting point. PDF versions are floating around online. Mass production will decrease the cost significantly.

  • AK

    Annika I just realized I am following your tumblr! Looks like a cool design, we need more affordable 9mm carbine options out there, the $700 ones are missing the market I think.

  • Nicks87

    Just make sure it comes with the FRS-15 California stock. I want people to think I’m from the future when I’m out on the range.

  • Tim Barrera

    If you look hard enough from time to time you can find Sten uppers that were converted to run on AR lowers. Pretty much the same thing….

  • guy


  • Noel

    Great idea, I’ve thought of similar concepts making further modularity options to the AR platform, but more for the sake of using cartridges longer than 5.56×45. Another option that I would appreciate would be a 30 carbine rendition of this, going back to the concept of side stepping mag well conversion. I read Olympic made a 30 carbine upper and the mag well conversion to m1 carbine mags never worked right. Being able to swap the mag wells in keeping with the same caliber would be a brilliant option for pistol calibers too. Although Glock would be the most logical offering, oh how sweet if one was able to share magazines with a wide selection of pistols one happened to already own.
    Something I’ve been contemplating, to take this line of innovation further, is, what about a tube magazine on top of the barrel with the mag well ejection? It would be a whole separate complete upper package I realize, but imagine a .357 trapper or .500 S&W bush gun all without having to have extra firearms transaction paper trails. It would be something cool for places that are tyrannically restricted like CA as well, a new genre in the shooting world in the vein of the Mossberg 464 SPX 30-30, I dubb “tacti-Fudd”!

  • Andrew

    The FG-42 was a freaking powerhouse. This looks more like a long barreled sten with better parts. Particularly because the designer wants to use glock mags.

    The issues i would have with the design is the weight of a magazine possibly throwing off your vertical sight radius causing people to routinely sling rounds to the magazine side (i would switch to the left, like the sten, so that more people’s support hand could manipulate the magazine).

    I would contend that if this is an attempt to throw a slidefire on a pistol caliber carbine, then either slidefire needs to pair with keltec and work on an addition to the sub-2000 which already accepts glock magazines.

    • Andrew

      I said either and then didn’t finish my point…sorry. OR a dedicated pistol caliber carbine accepting glock magazines in a side loaded configuration should be produced that doesn’t need an ar-15 lower receiver to function.