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Back in the day, H&K’s roller lock based MP5 was the end-all be-all of coolness. The soft-recoiling yet hard-hitting 9mm submachine gun was universally beloved by all the guys on the tip of the spear, and the gun’s popularity is reflected in the number of on-screen cameos it enjoyed throughout the last quarter of the 20th century. But despite being the apex predator of its day no one bothered to try and improve the gun. H&K moved on to other designs and the MP5 was left to languish over time. The boys at Brethren Armament think that’s a crying shame, and have dedicated themselves to bringing the MP5 out of the stone age . . .


Brethren’s now making MP5s from scratch. And when I say scratch, I mean scratch. They do their own manufacturing from the receiver stampings right down to the trigger group. While this might look like an MP5 on the outside, it’s 100% American made.

Because they own the manufacturing process they can do a whole lot more than small external improvements. They’ve recently gone through some ownership changes, and the new boss has dedicated his life to, and I quote, “fixing the MP5.” Starting with an integrated Picatinny rail on the top of the gun, a keymod handguard instead of plastic, and an extended magazine release paddle, the changes they’ve made so far are mere peanuts compared to what’s coming down the line.


One of the most ambitious projects they’re working on is fixing the trigger pack. The current design is enough to make any armorer weep tears of pain any time it needs to be disassembled, and for shooters the mechanics leave a lot to be desired in terms of the look and feel. The grip is fixed and unchangeable, the safety selector is awkward, and the pack is too big for anyone but a samsquanch to hit the magazine release button. But Brethren’s got a design coming down the line that fixes all of this — one that will accept a standard AR-15 trigger pack, safety selector and grip, and moves the whole assembly forward to make the magazine release button position actually make sense.

That’s all in the works. But for those who can’t wait, they’ve already got a line of American made guns ready to ship. What started as a custom gun shop is now turning out a line of ready-made MP5s in stock and ready to ship. Billed as a “proper in-spec” MP5, these guns are manufactured to the original specs of the firearm and are some of the best-put-together examples I’ve seen. A Pakistani Ordnance Factory MP5 might be cheap and made from original German tooling, but it doesn’t hold a candle to the refined look of Brethren Armament’s wares.


Their tinkering doesn’t stop with the MP5, either. They’ve also redesigned the HK43 to take standard AR-15 magazines, something that design sorely needed. The example above is chambered in 5.56 NATO, but they also have guns available in .300 AAC Blackout with more varieties to come.

Needless to say we’ve asked for some test samples to put through their paces. Stay tuned.

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    • Which model are you referring to with the warped rails? There are some improvements in the pipeline that will make that literally impossible, but we have yet to have a gun come back with warped rails, and we have some with round counts over half a million. Bulges in the back from bolt bounce is a concern, but when it is set up right and with the right end cap, its not an issue. We even designed a new end cap, and have several more on the way, to specifically address that. Feel free to hit us up with your specific concern.

      • It’s a shame you don’t export to those countries that’d willingly (and entirely legally) be able to import your wares in either pistol, rifle or what the US refers to as SBR form.

        At worst, consider appointing an export agent for such sales. At best, consider doing it yourself in a limited circumstance with a specified commercial importer (we can nominate one if required).

        Where we are: Switzerland.
        Seeking: Several BA33 models, SBR size.
        Who we are: Australians, living in Switzerland.
        Reason: While original HK33’s are not hard to find here, Switzerland has a ‘once full auto, always full auto’ law which puts factory full auto units onto a permit type that means you can’t shoot them. And we want to shoot these things, so factory semi is the requirement.

    • we started hand building them one at a time first to insure we wrung every bit of performance out of it in its current form. With that data, we were able to release the factory 9mm models. More models and caliber in that price range are on the horizon, but we prefer to take our time and do it right the first time. Please tell me you aren’t mentioning the price with a salient arms glock tucked in your waist band

      • That’s just for a base model. I just played around on their site and I had one in the cart over $3800, and I didn’t even select every option.

        • It will take time, but we have a lot of experienced engineers signing on from the automotive industry to optimize our production systems. The President’s car is a 10 year old toyota with leaking valves, and the VP still has a day job, so we are not vacationing in bora bora while we sell you overpriced guns. In time, we hope to have an affordable option for each caliber, but the “good fast cheap” triangle dictates that its going to take a bit.

        • If they made a roller-delayed version of the HK SMG-2 I might consider that price, otherwise I’ll stick with my Factory HK that will actually hold its value.

      • Dear sweet heavens. If it was a grand less, I’d consider it at least a far off “someday” gun, and for two grand less I’d chomp at the bit and throw my wallet at them.

        At that price it’s asking to lounge forever in Nobody Really Cares niche of the gun industry because they priced even FNH and most boutique guns out, short of European hand-made-and-gilt masterworks.

  1. Very impressive… Reminds me of Robinson Arms but with a better road map… Thanks for putting Brethren Armament on my radar…

  2. Practically, what does an mp5 do that a glock17 does not in trained hands? There, i said it… And i ll take my suppressed 10″ AR any day of the week

        • What makes you think 9mm does not benefit from longer barrels?

          Looks like something in the ballpark of 10% velocity loss going from MP5 barrel down to carry pistol sizes.

          10% can be nontrivial; not earth shattering, maybe, but non-trivial. Lots of real-world situations where one would GLADLY take a 10% performance boost.

        • JR, funny thing is that was the exact source from which i drew my conclusion. FMJ it wont matter as the temporary cavity is still not intense enough. If a JHP wont work out of a 4.5″ fullsize duty gun something was wrong with the ammo designer. For that performance increase to matter, you are reaching distances at which you hold over real high. JSP might benefit but who uses those in 9mil.

        • I’m no marksman, but could comfortably plink away at 50yds, and fairly reliably at 100 with even run down, refurbished military MP5s. The longer sight radius, plus the stock obviously, have their benefits. People who carried them, didn’t do so JUST to look cool.

          I still suspect an MP5 would be THE tool to have for protection against a determined bear charge. Would be cool if Brethren did a version designed for that purpose, with more outdoorsy than tacticool design cues. Military/police tactics and practice have largely left subguns behind anyway.

        • “If a JHP wont work out of a 4.5″ fullsize duty gun something was wrong with the ammo designer.”

          I’m not sure what point you are really trying to make. Who cares if the ammo “works” in a 4.5″ barrel. The MP5 is not an ED concealment weapon and has a very different use profile than a handgun. If the ammo works at 4.5″ barrel velocities, it will work more reliably with a 10% performance boost (ie, better penetration through intervening barriers/cover, etc) as might be encountered in the kinds of situations it was designed for.

          The point I’m trying to make is who would throw away a 10% velocity shot if they could get it? Your statement was that the longer stock was the only advantage that matters over a handgun.

          The advantages are not a laundry list of independent pros and cons. It’s a consolidated whole. It’s the 10% improvement in velocity, in combination with the other differences compared to a handgun that give a net “better weapon” for things like dynamic entry.

          You said: “Practically, what does an mp5 do that a glock17 does not in trained hands? “

          If I was in the stack on a dynamic entry for say a hostage rescue with multiple baddies inside and I had to choose between a Glock 17 and an MP5…is that even a choice? There’s simply no comparison.

    • The Glock, and almost all other pistols for that matter, rely on a tilting barrel mechanism for cycling. While this makes sense for the compact size and engagement distances they are designed for, it is impossible to achieve the same accuracy of a fixed barrel mechanism. As a bonus; the barrel can be made truly free floating, something the AR is incapable of. There is also no small gas tubes to foul up, and even before we really start tinkering with the system, there are no permanent aspects of manufacturing like gas port diamater that dictate how it functions. Its a quick change to dial the gun in for any configuration, load or application (with more on the way.)

      • I was never bashing the roller delayed blowback. Just thought a 9mm doesnt deserve to be over 6lb given its application if it’s not just a plinker. Since you brought that topic up, even a DI AR can have a adjustable gas block if you need one. Making different assemblies to be swapped out in the bolt is no easier than the adjustable gas block mated to a properly made gas port. As for the barrels, gas operated guns cannot have freefloated barrels but freefloated handguards enable you to not flex the barrel plus the gas system, which is the whole point of “freefloated barrel” on an autoloader. The reason why bolt guns still exist is that they have the least variables. The moment a roller-delayed fires, the bolt assembly begins moving. Not twice does the same bolt move the same; not twice does the same spring compress the same. These all factor into the bullet’s precision. The same applies to gas guns, with all the gas system and bolt carrier group involved before the bullet leaves the muzzle. Neither is better than the other, precision wise. There is much more to precision than freefloated barrels, all of which is irrelevant when you shoot a 9mm for CQB, or hold over one foot over your target.

    • more or less. That also has a flared magwell, and a straight pullback charging handle as opposed to the lever style. theres more to discuss, but those are the highlights for now.

  3. The HK rifles (91/93/94) were my first love and got me into the shooting sports. And reliable, accurate, durable–they’re unmatched. However, it wasn’t until I got onto an AR that I realized I was living in SLOW MOTION–the ergonomics of the manipulations of the HK series of rifles is hideous in comparison. There was one improvement in this regard that they mentioned–fixing the mag release position (actually the trigger pack size) so it can actually be manipulated by the index finger on the firing hand, allowing you to eject the magazine without actually grabbing it with your support hand or flicking it out AK-style with the new mag. That’s a huge improvement, yes–that will cut reload time in half. Or maybe a third (see other remaining issues #1 and #2)

    Other huge issue that needs fixing before this thing is out of the Stone Age is a Bolt-hold-open on empty. C’mon, will ya get this fixed. Having to count up to thirty while firing in order to avoid the dreaded “click–Oh, I’m empty” is just lame. Yes, it will require figuring out how to have a bolt catch that isn’t the charging handle locking into a recess in the receiver, and maybe that’s a non-starter. But without this, you just can’t come close to the speed of the AR platform for mag changes.
    The other huge drawback of the current manual bolt hold open is having to slap the charging handle down and away in order to insure that the bolt goes back into battery–terrible! The last thing you want to do during an emergency mag change is hit the gun down and away, rather than bring it back up into firing position.

    All of this is solved with an automatic bolt catch. Just make this change too as you import the AR system that you’re planning to import to fix the trigger and the mag release button, and you’ll really fix this beast.

    Oh, then you could jettison the $85 HK magazines and replace them instead with–Magpul magazines for $12.95. Get on that Magpul. Or maybe use the CZ magazines.

    Of course, you do all that and then you have–an AR in 9mm. Oh, wait, we already have that. And the MRX, and the CZ, and the B&T, etc. etc.

    I dunno, maybe it’s just time to call time of death on this HK system. Sure looks like HK already did.

    Fix that bolt catch thing and we’re back in business.

    • Run a shaft up the back of the magwell like LAR-8. Modify the follower and mag body. Boom, ambi bolt catch. Remove the current bolt catch notch and run the charging handle like an AK. problem solved. Good plinker

    • HK actually fixed that at the FBI’s request. The 10mm MP5’s the FBI ordered have the last round BHO feature.

    • HK actually did make a bolt hold open system, but it was only applied to the 10mm and 40S&W models. Even before the new trigger pack hits the market, we have a short term solution for the magazine release issue; a bolt on sleeve that allows release of the magazine with the trigger finger. Its not a perfect solution, but it is a big start.
      Here’s a link to it.:

      Rest assured the bolt hold open issue is a top priority, and several options are being tested currently.

      Our own US made magazines ( that will still function in your original German play toys) should be available on HKparts as of next week.

      It may be true that this horse is truly dead; were not under any delusions that throwing money at it will make it useful again. But were former trigger pullers, that became engineering and manufacturing people, and are going back to what we love. There are some interesting characteristics of this platform that those other guns just don’t have, they just need some modern thinking applied. I guess time will tell

  4. I think the only thing more useless than an expensive semi-atuomatic submachine-gun would be an expensive semiautomatic belft-fed machine-gun….. oh, wait, this gun requires a tax stamp? Never mind, it wins the useless contest.

    • One thing that for sure is more useless than a $4K semi-auto subgun, is a $4+trillion government that prevents one from buying said subgun in it’s proper full auto specification.

      For whatever reason, it seems like the fashion of the past decade or two, has been to indiscriminately pooh-pooh subguns. The military is understandably better served with Carbines that can reach out further without nowadays being much bigger nor heavier. But based on the all too brief period when I had the opportunity to shoot and practice a bit with them, they have an absolute shit ton of positive attributes for anyone without any business shooting at stuff defensively past 75-100 yds.

      Compared to an M4 they are, even wide open, as quiet as a library. And they shoot rounds optimized for close in work. Making them close to ideal as “ranch carbines” for the size of “ranches” most people realistically own these days. The relative quietness also makes them much preferable to 5.56 for civilian indoor use, easier to find places to practice with etc. And for a woods gun, I doubt anything covers the spectrum from bear to wolfpack to mountain lion to two legged predator better than an MP5 in the hands of someone with even just moderate training.

      They’re not really compatible with the “held accountable for every round” mindset that prevails in many circles today, but then again neither is the currently fashionable protocol of just blasting away at the “threat” until the slide locks open.

      Anyway, they’re a cool and currently underapprecioated class of firearm. I suspect they will have their moment again.

    • Standard configuration for all models is a pistol, and we can even do your Form 1 engraving at the factory if you want.

      We also have two models that are available for under 2k, and after we spend some time in the nerdery, hope to get that price down considerably.

      Its all on that website we have that you didn’t look at, along with the information that we have actually been around for 3 years, and in the manufacturing industry for over 12. but hey, buying a 9mm AR dressed up to look like one of these guns is cool with us too.

  5. Oh my, they also make the MP5 pattern guns in 10MM and .40S&W. But the 10MM pistols run $3100-3300ish.

  6. $3899 for a MP5 clone from a start up gun maker? Are you f*****g kidding me? There’s a wide selection of Carbine’s and SBR’s available on the market for half of that ridiculous price. Hell, for that kind of money you could own both a Sig MPX and a Sig MCX. Definitely a niche market firearm targeting either wealthy gun enthusiast who don’t care about the price or gun nuts with more money than good sense.

    • “Definitely a niche market firearm targeting either wealthy gun enthusiast who don’t care about the price or gun nuts with more money than good sense.”
      Well there is another option there, and that’s people, like me, who have shot the holy crap out of the MP5 and UMP45 and find it shoots better than any AR platform gun in those calibers I’ve ever used. And I’ve shot the hell out of those as well.

      • Thanks!

        I’m fall very far short of “the hell out of” mark, but my more limited experience with them, left me much more impressed with them than the currently incessant internet pooh-poohing would warrant. Widespread use of body armor may end up being yet another nail in their coffin as tactical choices, though….:(

      • Sure you have J Dub. Couldn’t help but notice you didn’t specify why you believe it “shoots better”. A suppressed select fire MP5 clone? You betcha! $3899 would be a bargain, but that’s not a legal option. If you’ve got the cash to blow after convincing yourself a MP5 clone from a start up outfit that likely won’t be around 5 yrs from now is worth double the cost of a Sig MPX, go for it!

  7. A spokesman from Heckler und Koch screamed obscenities and then “You suck and we hate you!” just before his head exploded in a massive cerebral hemorrhage.

    A second spokesman elaborated his colleague was upset with the apparent tinkering with H&K’s Teutonic perfection.

  8. “The soft-recoiling yet hard-hitting 9mm submachine gun …”

    Huh? In my world 9mm Luger is not what I would call hard hitting.

    Now, if that submachine gun were chambered in 10mm (which apparently is available according to Reef Blastbody’s comment above), that might be approaching something like “hard-hitting”. The website Ballistics By the Inch indicates that a full power 10mm round with a 180 grain hollowpoint bullet would exit a 9 inch barrel at 1500 fps. I’ll take a 0.40 inch, 180 grain bullet at 1500 fps every time over a 0.35 inch, 125 grain bullet at 1350 fps.

    Of course “more is better”. If a submachine gun was chambered in .357 Magnum and had a 9 inch barrel, you could expect muzzle velocities of 125 grain bullets upwards of 1850 fps. Now THAT is hard hitting.

      • Of course … but who wants to have to put an entire 30 round magazine into an attacker to stop the attacker? A double-tap of 10mm seems highly preferable to 30, 20, or even 10 rounds of 9mm.

        • I am very, very far from some sort of Clint Smith as far as gunfighting goes, but unless you have had a chance to practice even a little bit with MP5s at common pistol targets, you are likely underestimating how easy they are to do serious damage with. At the typical 7 yards, I could probably lift a shoulder slung mp5 and unload an entire magazine at a “combat target” in the time it would take me to present and double tap with a G20. And at 25+ yds? Fawgettaboutit…. And once I turn 90, I would still remain equally effective with the MP, while the G20 would break my wrist off halfway through the doubletap maneuver…..

          I keep coming back to the charging grizzly. Still can’t think of anything reasonably portable I would rather be armed with in that scenario, than an MP5. Aside from perhaps an MP5 with the entire magazine stacked with tracers….Heck, one of subguns’ standard justifications, used to be their effectiveness in the dynamically rather similar situation of stopping a car trying to speed through a road block/gate……

  9. Like the look, love the AR mag option. Honestly fixed ergos and the addition of an optics rail, forward rail/handguard system pretty much covers all that is wrong with the MP5 by todays standards.

    The only thing that makes me nervous is them messing with the internals. If they get it right I am all for it, if they get it wrong… I hope that they can manage to fulfill the promise on all of these. The only problem left at that point is price, which can be justified if the promise truly is fulfilled.

    • I am the chief engineer here, and it scares me just as much. Its not something we take likely, and me and my fellow nerds will either make it work, or not at all. But us “tinkering” is a far cry from what has become the norm in the industry. We do the math, run the computer simulations, test it the same way the car you drive is tested, and only if that all works, does it go to market.

      • That’s actually really good to hear, and does a lot to explain the prices. Good R&D isn’t cheap, bravo sir.

  10. Nice. To avoid Obama’s libtard import ban, all designs from other countries should also be made here. Liking it.

  11. Most people get HK clones because they want an HK. I have a rifle with an AR15 trigger pack in it…it’s an AR15. The stock on the brown one is horrid… nice chin weld. At those prices, you could save a little money and get an real HK.

  12. Well, thanks to TTAG for the awesome write up.
    So yes, the hand built models are pricey. This is due to the cost of parts, and not necessarily the cost we add to build them out. A parts kit alone can run from $1300 to $2000. But, each gun takes approximately 8-10 hours of actual build time, from start to finish.
    Now, our production guns, which are also offered on out website, are $1899. These are ready to roll as a basic model.
    The mag seating issue for the AR15 mag conversion has been corrected and they will run HexMag, PMags or any other AR15 mags out there.

    As for the items that are coming out soon, much within the Roller Lock platform is being addressed and re-worked, one area at a time.

    Any questions, please feel free to contact use. Or, stop by the Silencer Shop Booth at Texas Firearms Festival this Saturday and Sunday to meet us and shoot some of our firearms.


    • Parts kits? ‘Brethren’s now making MP5s from scratch. And when I say scratch, I mean scratch.’

      Which is it, parts kits, or scratch?

  13. Sear ready?
    My trigger pack or yours?
    Shelf not double push pin, yes?
    Full auto HK53A3 in 300 BLK?
    Oh my
    Once my registered sear or trigger pack is in, will you provide stock?

  14. The truth about Brethren Armament is they are liars, cheats, and crooks. Goto their Facebook page and read the 1 star horror story reviews.

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