The HK PDW: The Origins Of The MP7

Though rare in the wild, mostly seeing use with special units and some police departments, is a favorite of Hollywood movie-makers and Triple-A video game developers, thanks to its compact size, striking looks, and fully automatic firepower. The gun itself, however, was originally intended to be an inexpensive, compact, and unobtrusive weapon that would be better for troops far from the front, the MP7 eventually became a weapon more commonly associated with the tip of the spear, direct action teams, and SWAT officers.

The MP7 began life in the last year of the 20th Century as the Heckler & Koch PDW, which was intended to compete directly with the Fabrique Nationale P90 in NATO trials to standardize an echelon weapon for second-line troops, vehicle crews, and support personnel. Below are embedded two documents from that period, a presentation given at the 2000 NDIA Small Arms Symposium, and H&K’s brochure for the prototype weapon:

The resultant MP7 differed somewhat from the PDW, in that it was heavier (1.9kg/4.2lbs vs 1.6kg/3.5lbs) had a longer rear receiver, a flash hider, full length top Picatinny rail (deleting the molded in fixed iron sights of the prototype), taller buttpad, and mounting points for rails on the sides of the forward receiver housing, all changes which hastened the PDW’s evolution from a dedicated personal defense weapon to a more generalized submachine gun that could be used equally well by echelon troops or direct action teams. This evolution is ongoing today, as Heckler & Koch recently released the MP7A2 variant, which does away with the folding vertical foregrip of previous versions in favor of a tri-rail mount.

Below are embedded two videos, one that is an action spot of the MP7 produced by Larry Vickers’ channel, and the other is a slideshow produced by Heckler & Koch about the MP7A1. Straightgrain, the channel hosting it, also has some excellent videos demonstrating the terminal ballistics of the MP7’s suite of 4.6mm ammunition.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • hami

    In early 2014 H&K’s Wayne Weber gave an exclusive interview to HKPro members at Shot Show. He hinted at the possibility of a .22 version of the MP7 from Umarex, who H&K has a licensing agreement with.

    I have kept my eyes peeled ever since, especially considering that Umarex’s G36 .22 rifle showed up early this year almost completely out of the blue.

  • ostiariusalpha

    Crying out loud, HK! You don’t need the archaic cheese grater 1913 rails anymore, just use a negative space attachment system like M-Lok or KeyMod for any modular accessories and at least try to look like you even care about being innovative anymore.

    • Joe

      While I understand the weight savings i have to disagree with you here, there is nothing wrong with 1913 rails. The keymod system needs to stay where it originated….in the home improvement isle at home depot. And the M-Lok system is just another way for companies to sell you crap you already own. I mean really how often are you taking off your accessories? If its on the gun leave it alone.

      • ostiariusalpha

        The M-Lok system is just as secure, lighter overall, less pointlessly fat, considerably less expensive and time consuming to produce, and frankly just better looking than the Picatinny rails, which is what is “wrong” with having the 1913 anywhere but the spine of the gun. Considering that any practical weapon should use accessories sparingly, why would you have so much of your handguard devoted to rails that eat up space and add weight for no particular benefit? It’s not like these rails are sleekly molded into the frame of the MP7 either, they’re just tacked on, while the original forend already had vent holes that could have just been opened up a bit to become attachment points. As for KeyMod, if people want penis silhouettes on their guns, I try not to pass judgement.

        • anon

          >penis silhouettes

          I laughed.

        • Joe

          Like I said earlier he M Lok system is lighter and thats pretty much whats its got going for it. On a manufacturer side it might be cheaper to make but since everyone and their mother has tooled up for making pic rails in spec it’s a moot point. Also I’ve NEVER ran into anybody at the range that said “Hey Joe, do these pic rails make my gun look fat?”. If you like the look of the m lok system thats awesome (i think its an interesting design) but there is a reason why the “old” pic system is still king.

          • ostiariusalpha

            On the range?! C’mon now, be serious. The entire sport of rail-mounted benchrest shooting only exists because nobody has to care how much their crap weighs at the range. Mr. Alex C. has already pointed out that your range buddy isn’t going to be getting an MP7 anytime soon, so that opinion is the moot point. Professionals that shoots at people, not just targets, have expressed dissatisfaction with bulky quad rails ever since they first came out. The only thing that much pic rail is good for is stowing the even more useless detachable carry handle that many of them are required to have on their person.

          • Joe

            Again i’ve never had a problem with pic rails. Clearly you are not happy with them.

        • Kivaari

          But, they got us to where we are today.

    • The MP7 is for sale primarily to military forces (zero civilian sales allowed whatsoever). Military forces use 1913 rails. So, the MP7 will have 1913 rails.

      • ostiariusalpha

        Actually, the kind of specialized agencies and military units that would use the MP7 often have weapons with non-standard and particular attachment systems in their armories. There are rifle handguards with proprietary screw spacing for attaching pic rails and, truthfully, you can just attach rails to an M-Lok slots if that’s a real requirement.

        • Hk cannot cater specifically to what one small specialized group may or may not have dude, so they just go with the universal 1913.
          That said, I promise you if a large enough order was placed they would make whatever the customer wanted.

          • ostiariusalpha

            If HK used the M-Lok system, they’d be in a pretty good position to cater to whatever specialized whims said group might have. Want picatinny rails? There you go. Want a AK-style side mount for some reason? So be it. And they come right off if they change their minds. It doesn’t have to be M-Lok, of course, but any negative space attachment will be more flexible and less cumbersome than tacked on rails.

      • Andrew Marcell

        Except in Canada …

        • The ones in Canada aren’t supposed to be in civilian hands and trickled onto the market via unusual channels. HK was very upset about that.

    • SP mclaughlin

      The side rails are already removable, and the top rail wouldn’t affect ergonomics.

      • ostiariusalpha

        I’m not really concerned with the top rail, and you’ll never see those side rails being removed for comfort or convenience.

    • tony

      since when did 1913 rails become obsolete? Kids these days…sigh

      • ostiariusalpha

        The MIL-STD-1913 was adopted just over 20 years ago. So yeah, it’s kind of showing it’s age.

        • Kivaari

          Wow, 20 years ago. They still work well for optics in common use. Staying with them at the 12 O’clock position makes sense today, probably will 75 years from now.

        • DIR911911 .

          tell that to the boom end of my 1911

          • ostiariusalpha

            Your 1911 is a fraud, sir!! How dare you boast of such a heretical abomination! Such vainglory, fie on you for polluting the purity and grace of John Moses Browning’s blessed creation! Let the garnering commence!

            IRE!! IIRRRE!!!
            IRE! Ire! Ire!
            Ire, ire, ire, ire…

            I bet it looks nice. How does it shoot?

        • Anon. E Maus

          Rails are still excellent for mounting optics, top-rails will continue to be a thing.

          I definitively think that KeyMod is a better option than quad-rails, keeps weight and snag down.

      • Jwedel1231

        Man, old people these days. Sigh…

    • HKGuns

      1913 Rails are hardly obsolete.

      • ostiariusalpha

        As optics mounts, you are correct; as accessory mounting points they are not at all ideal.

    • Steve

      You know this gun came out before MLOK or keymod was around, right?

      • ostiariusalpha

        You know the MP7A2 came out last year, right? ?

        • Steve

          Never paid attention due to multiple reasons.
          1. The caliber. Who the hell wants to defend themselves with .22 magnum?
          2. It’s HK. The epitome of overpriced mediocrity.
          3. LE only. HK because you suck and we hate you.

          Also, how is that statement relevant? Since when has HK ever listened to end user input? If you want HK to fix things, try getting them to put mag releases back where God and John Moses Browning intended.

          • ostiariusalpha

            I like the trigger guard mag release better than fine, in fact I have a preference for using my index finger. Thumb releases are better than heel releases, but that’s about it. With using my index finger to drop the mag I don’t have adjust my position on the grip.

          • iksnilol

            .181 magnum if you want to be more correct.

    • spitfirerobinson

      Wait…… Don’t people use M-Lock and KeyMod to attach 1913 rails to just where they want them?

      • ostiariusalpha

        Yeah, I think that gets mentioned somewhere, so keep reading.

    • n0truscotsman

      I agree. quad rails would have died a well-deserved, agonizing death a long time ago 😉 I just like the option of either running rails or running slick, not having to decide between the two.

      Midwest has some nice ones that aren’t too expensive. Geiselle’s are excellent.

      In fact, come to think of it, I dont think I have anything with quad rails anymore.

    • Cal.Bar

      Are you REALLY worrying about the rails on a gun that virtually NONE of the regular citizens in this country will EVER touch, much less own?

      • ostiariusalpha

        LOL! I’m sorry Cal, but are you REALLY concerned about whether I’m concerned or not? You don’t find that just a tad hypocritical? But all razzing aside, I’m not shy about expressing the wish that HK would be a little less like Colt, and a little more like the ambitious, innovative company they were before the 90’s; even if it’s just baby steps like accessory attachments. Don’t get me wrong, I really like my VP9, but I’m not going to pretend any of it’s features are anything other than incrementally different from other striker pistols on the market.

    • whskee

      Last I checked, there was no mil-std-mlok or mil-std-keymod, and that is the major difference. Companies want to conform to an accepted standard that is as internationally recognized as possible, because it works with more of the intended market. The vast majority of accessories on the market are still 1913 focused. M-Lok and KeyMod are great, but they are still the minority system.

      • ostiariusalpha

        Last I checked, the specialized organizations that use guns like the MP7 have more than a few weapons in their arsenals with attachment mounts that you won’t find a milspec for. I’m pretty sure that I pointed this out before too. The MP7 is never going to be a standard issue armament no matter how many Picatinny rails it has. I also pointed out that it’s not a problem to just attach the 1913 rails to the M-Lok slots, if that’s what the customer really wants.

  • John

    >Though rare in the wild, mostly seeing use with special units and some
    police departments, is a favorite of Hollywood movie-makers and Triple-A
    video game developers, thanks to its compact size, striking looks, and
    fully automatic firepower.

    It’s a German plastic Uzi in a unique caliber. That’s all it is, really.

    If HK really cared about their MP5, they’d have offered it with better stocks and various rail systems by now.

    • Ben

      The MP5 is dead as far as new orders go for professional use.

      Pistol calibre carbines don’t do anything that a 10″ 5.56 SBR does better, and they a lot of things much worse.

      • iksnilol

        They suppress much better.

      • Chase Buchanan

        Pistol caliber carbines can more easily be made to not instantly blow out your ears.

  • Vitor Roma

    The second video that is actually a power point presentation is a must see! Especially the rounds, the ultimate combat seems like a nasty little fellow.

  • Lobo Rojo

    Looks like Keltec gave a makeover to the Uzi.

  • Jeff

    Would you put your life in the hands of a round that duplicates only .17HMR?

  • mechamaster

    I imagine the headline ‘H&K PDW’ is the prototype G11 caseless PDW. But it’s about MP7. lol

    ( picture borrowed from hkpro ).

  • KoyoteTan

    I think that we all know the true origins of this gun in Half Life 🙂

    • Chase Buchanan

      I instantly recognized this from Half-Life 2. I always thought it looked vaguely but definitely not exactly like an MP7. Now I finally know where the Half-Life 2 SMG comes from.

    • Matt Shermer

      Except when some games designer said, you know what we have to bring back? Rifle grenades, and then make players scratch their heads wondering where the hell the launcher was…

  • ostiariusalpha

    oh, for f*ck’s sake… Bro, that’s an MP7A1, it doesn’t have any accessory mounts on it to even remove; the MP7A2 is the one that just came out with the 1913 rails.

  • ostiariusalpha

    MR556 = Civilian rifle. That’s why they felt comfortable with the KeyMod handguard. The military contract HK416 series always has the massive quadrail on it.

    • Wetcoaster

      Not too many civilian markets for the integral suppressor. Hence my surprise they used the MR556 instead of HK416 designation

      • ostiariusalpha

        There’s plenty of market for integral suppressors, that’s why people make them. Even if there weren’t, the OSS suppressor on the MR556A1-SD isn’t integral to the rifle. It mounts to a special muzzle brake.

  • Anon. E Maus

    Should have been in 9mm Luger.
    And delayed blowback.

    It’s a cool gun, but the B&T MP9 is just more practical.