HK MR556 SBR (Civilian HK416)

The H&K MR556 rifle is essentially a 416 without select-fire capability, but this video showcases an MR556 that has been brought up to near 416 specs. With a chopped barrel and a few other modifications, the gun could fool all but the most discerning onlookers. So, how does it shoot?

Transcript …

(rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) – Hey guys, it’s Alex T with TFBTV, and today we’re taking a look at my H&K MR556 SBR that I tried to get as close in appearance to an H&K 416D as possible.

All in all I think it’s a little project that’s turned out pretty well, and in my opinion the gun looks very neat.

Basically I started with a used HK MR556 that I got for a song, paid for a stamp, cut the barrel down to 10 inches, had selector markings engraved, had the barrel reprofiled.

Anyways the 416 is a carbine that really is making some waves around the world.

Essentially it’s an M16 with a short stroke piston, but a very well made version of one.

They also just have a lot of features a lot of people might like, like the stock comes from the factory with the ability to store batteries, tools, whatever.

However I found that it’s nice for keeping NFA paperwork there, this is the Form 1 for the tax stamp.

There’s also another one, a Form 4 for the suppressor I occasionally mount on there.

You can also take the butt pad off and put a concave or convex one on there if you’d like.

Right here’s where you can store batteries in the grip, not a unique feature to this gun, but it comes from the factory like that.

Now the magazines are where I’d like to give a little bit of praise, they’re interesting.

They are coated in a maritime-resistant finish that allows for 96 hours worth of saltwater corrosion resistance, a little excessive for me as a civilian.

Another interesting feature is there’s a small round rubber buffer on the floorplate that holds the whole magazine together when firing grenades.

The rear iron sight is adjustable for windage by pressing down this little detent and rotating this knob.

And it does flip down for storage or running an optic or something like that.

You’ll adjust it for elevation by pulling this up and rotating it.

Interesting iron sight, well thought out, and one cool thing is how it removes, you actually pop it off by pressing this backwards and pulling it right off there.

And it actually does return to zero when you put it back on the Picatinny rail system, which is nice.

The front sight does not have any adjustment, but it does fold flat, in case the user is running an optic, and they don’t want it to interfere with that.

So that is a nice feature as well.

It attaches right to the gas block and it does get very hot.

Now to remove the handguard, first pop off your rail cover if you’re running one like I am.

And use a hex key, and go ahead and unscrew this bolt.

I have seen videos of guys in the military using the actual bolt lugs to undo this, but I’ve also seen people advising against that, for obvious reasons.

And here you can see the piston system.

If you’re familiar with the G36, it’s actually very reminiscent of it.

But let’s send a few more rounds downrange suppressed.

(rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) If you’re comfortable shooting an AR-15 rifle then really the MR556 and by extension, the 416 should feel pretty familiar to you.

Aside from being a bit more front heavy than a DI rifle this gun has no special or unusual handling characteristics.

The trigger’s a bit lighter than a standard semiauto AR-15 trigger, so that’s nice, and the stock and grip from the factory are both really comfortable.

The E1 stock while a bit large and bulky offers a great cheek weld, and of course you could simply put one on any other AR-15.

(rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) (rifle fires) So at this point I thought it might be neat to showcase the piston system in action.

This is full speed right here, so obviously you really can’t see anything with the naked eye happening up front.

As it does happen at an incredible amount of speed, but at first I’m going to slow it down real quick to one-quarter speed, and you can see it jump just a little bit.

But then we slow it down to one-tenth speed, you can see the piston and op rod jump quite a bit.

Pretty neat! So at this point it’s time to move on to the accuracy portion of the test, let’s go ahead and remove that rear iron sight.

You don’t really have to do this, it does fold down, but I like the optic to be pretty far back on most of my rifles, so it’s easy just to pop it off with this iron sight.

And I’m using a 4X ACOG with some arm’s throw levers, because I do like to switch it between guns for testing.

So using my Polaris Ranger as a makeshift shooting bench until I can finish my two shooting benches I’m currently in the process with, I shoot a couple of five-shot groups with standard M193 military ball ammunition so 55 grain ammunition out of a 10-inch barrel, at about 100 yards here.

I did not have time to do a 300 yard test that day but it is something I would like to revisit in the future.

I know this rifle is capable of great accuracy, after all, MR does stand for match rifle, at least as is my understanding, and HK’s excuse for not going to the chrome-lined bore was for enhanced accuracy.

I’d rather have a chrome-lined bore, but that’s just me.

It’s my understanding also that the new rifles either are coming with a chrome-lined bore or do have a chrome-lined bore so that’s good news.

But let’s go ahead and check out the targets and see how it performed.

So on the first target we printed a little over an inch, which was actually one of the best groups I’ve ever shot with this gun, I’m not going to lie.

That’s unusual to get a group that small with this rifle in my hands.

But the second group is a little bit more reflective of what I typically get out of the gun which is about two inches.

It’s a 1.6, 1.7 MOA gun out of all the groups I’ve shot with it.

I hope you guys enjoyed this video, I normally don’t show little pet projects of mine but I made an exception in this case.

It was requested, and yeah, I hope you enjoyed this video.

Thanks for watching and I hope to see you next time.

(rifle firing)



Alex C.

Alex is a Senior Writer for The Firearm Blog and Director of TFBTV.


  • Markbo

    What is the profiling of the barrel and to what end – why?

    • JumpIf NotZero

      It’s not a profile. That’s the suppressor mount / muzzle device.

      It’s Gemtech’s (mediocre) quick attach system called BiLock. It’s the same idea as three lug on the MP5, but missing a lug because…. It’s likely tighter tolerance as it’s for rifles, but I’ve never been impressed with it personally. IMO, it’s a step down from the tolerance of thread on while also being a step down from a secure ratcheting system like SiCo’s ASR (and AAC’s 51T before that). Geez, I think even YHM’s system is better and I really hate that one.

      • iksnilol

        Uh, have you seen an MR barrel under the handguard?

    • Originally the barrel’s diameter under the handguard is very thick on these rifles. I had a gunsmith turn the barrel down to proper 416 diameter/spec and with the proper step.
      Cut out quite a lot of weight too.

      • JumpIf NotZero

        He meant under the handguard? I’m… that seems like a pretty informed question to make. The kind that would be so informed it would negate asking it I think.

        Also… you did? I didn’t know the MR barrel was heavier than the 416. Hammer forged barrels are USUALLY ok to cut down without getting into disproportional stress relief if done right. It’s really too bad you didn’t test accuracy first.

        Because 1.7 MOA is pretty awful for an AR imo, and you could have had a whole different article based on the results.

        • Seems like a logical question to me. I stated that I had the service performed in the video, so he asked what I meant.

          But yes, the MR barrel is absurdly thick from the factory and resulted in a ludicrously front-heavy gun. IGF worked it over and it feels a bit better now. Key word is bit.

          • Rob

            The MR556 ships with one of the finest barrel blanks ever fitted to a rifle.

          • I once thought about making a video about the wacky stuff companies do to make stuff legal for importation, but I think that could be a bad thing. “Hey, look what we do to get around your laws!” has ruined a lot of good things for shooters around the world.

  • Black_Viper

    It’s black and scary looking, ban it.

    • ReadyorNot

      Shoulder thing that goes up.. BAN!

      • It may bring you pleasure to know that she is now retired.

        Our shoulder things that go up are safer.

  • Lance

    Fun toy Alex only problem as with any H&K product…. TOO DARN EXPENSIVE!!!!!!!

    • Orion Quach

      All very relative to each individual. Most if not all H&K pistols are cheaper than any of my dad’s 1911s.

  • gunsandrockets

    How is the muzzle blast?

    • Loud and obnoxious, like most SBRs.

      • gunsandrockets

        Have you ever tried one of those muzzle blast diffusers? I’m curious how well they actually work.

        • I have not, but I would give one a go. Couldn’t hurt, that’s for sure.

        • Mack

          They work quite well. I love my kaw valley linear comp. (basically same thing as a diffuser)

  • Minuteman

    Alex, as always, nice vid man. Keep up the good work. Just a side note: You have a nice, calm, pleasant voice to listen to. Ever considered going in to voice over work for documentaries etc?

    • That’s very kind of you!
      But no, I kind of like what I have going on in life these days. However I am considering a second channel focusing on different subject matter.

      • Major Tom

        Let it be pizza.

      • Giolli Joker


        • Yep!

          • Minuteman


          • kingghidorah

            I love ‘regular cars’, love to hear something on his line.

      • Minuteman

        You’re welcome. Ok, sure thing (y)

  • thedonn007

    Too bad tou cannot flip the front sight down when using a suppressor.

    • Yep. Sucks if you want the folding front post on the short barrel.
      The gun actually came with diopter sights mounted to the rail.

      • Jim N Jenna SK

        Where did you find that rear sight and is that what is on the 416 D?

  • JumpIf NotZero

    A 1/2 mention of weight when that’s got to be the biggest issue besides price. Ah, HK fanboys 😉

  • But here is a photo comparing a 416 upper and an MR556 one. The barrel on the MR556 is quite heavy due to the large diameter (which is why I had a smith reprofile it):

    • SP mclaughlin

      I guess that’s why it’s considered a “match” rifle?

    • Giolli Joker

      Well, If the rifle breaks you have a sturdy club.

    • ProLiberty82

      Are ordinary AR15 pattern barrels compatible with the MR556 receiver/gas block, and if not can they be modified to accept them?

      • Weaver

        you would run into a problem with the upper receiver as the MR556/416 has a slightly taller receiver. You can’t use a regular ar15 barrel on a MR556/416 because the barrel extension on the MR is also a little bit longer.

        • ProLiberty82

          Okay, thanks for the heads up! Think I’ll just go for a Colt LE6920 OEM and put an Adams Arms piston system in it plus some stainless/nitride/tool steel parts for ruggedness/longevity, I probably end up with spending quite a bit less on that then an MR556 and have parts commonality with the rest of the AR market to boot.

          • Minuteman

            You could also look at PWS or LWRC. They have very nice offerings. Demand for those rifles is very high and they’re quite often sold out. But the wait sure is worth while. Can’t go wrong with either of them.

  • A bearded being from beyond ti

    There’s something i’ve been wondering about the 416. They include the letters “D” and “RS” in the name for some of them, for example D10RS or something along those lines. RS seems to stand for Retractable Stock (which seems like a useless addition since i haven’t seen any 416 with fixed stocks) but i have no idea what the D stands for. Anyone know?

    • I got nothing.

      • A bearded being from beyond ti


    • HKmaster

      The D in HK416D and HK417D stands for “Defense” as in HK Defense USA. Essentially, any 416 with the D marking was designated for use in the United States. A 416 without the D marking was made for international use. Not sure what the RS stands for though haha

      • Chris22lr

        Are you sure of that? I think every European military using HK416 refers to them as HK416DxxRS. I’ve seen photos of Polish SF HKs and these are even marked with “D”. I think the only exception is Norway (their’s are marked HK416N for D165RS and HK416K for D10RS).

        • HKmaster

          Maybe those units may have ordered from HK USA? I’ve seen that French, Indonesian, Turkish, and Filipino HK416/417s are all marked without the “D” designation.

      • Minuteman

        Does it have something to do with the A5 version aka G38? I sure do like that one! Add Lancer mags, some Magpul/BCM furniture and the Geissele HK416 trigger in the mix and you’re good to go. The 416 series is very reliable in the piston realm, I reckon. But according to the Norwegian Army it doesn’t fair well in arctic conditions. Funny how they didn’t see that one coming during trials.

      • A bearded being from beyond ti

        You sure about this? Any source?

        • HKmaster

          Its not letting me post the link, but its a source from HKpro

  • Anon

    I don’t think this thing is worth three or more AR-15s, because I’m pretty sure it’s not three times better.

    • A bearded being from beyond ti

      It’s HK & Koch so obviously it’s worth it all day.

    • Hard to justify the price on these for sure. If I didn’t get a deal on a used one I would not have bought the thing.

    • Sermon 7.62

      It isn’t good at all. The barrel’s life is about 6,000 rounds, no other barrels are being sold and after all it’s just a piston AR15.

  • Green Hell

    Is the lower compatible with different AR uppers?

  • Jim N Jenna SK

    Yes more videos like this! Please and thank you.

  • HKmaster

    How’s the recoil compared to standard DI guns of similar length? I don’t know if its just me, but when i see other people shoot 416 platform rifles, the recoil seems to be more pronounced than the recoil from DI rifles.

    • Anon

      DI guns have the least amount of moving parts and mass, therefore, it makes sense to assume that all other things being equal, a DI gun recoils less, because it has less reciprocating mass.

      • Tritro29

        … That’s paradoxal…recoil is due to the mitigation of the force impulsed by the munition going bang to the structure of the gun while leaving the barrel. If the structure of the gun is geared towards reducing the felt recoil (think AN94/AEK971/3) you are going to have less recoil for a similar munition while both have MORE moving parts than the AK74…

        It’s a matter of structural integration of your firing mechanism and munition within the frame, not moving parts. Simpler doesn’t mean less recoil.

        • Anon

          …I was excluding “balanced recoil systems”, because those aren’t readily available here. I know that simpler doesn’t mean less recoil too, because otherwise Hi-Points would be the softest shooting pistols because they’re blowback operated, which they’re not, because reciprocating mass.

          I meant rearward reciprocating mass, excluding some mechanism that reduces recoil, which this MR556 certainly has more of than a regular DI AR-15, due to the piston.

          • Tritro29

            We’re in agreement, I generalized something trivial. My bad.

          • Anon

            It’s okay.

    • The_Champ

      It’s a .223, what is this recoil you speak of? 🙂

  • Sermon 7.62

    Not a bad carbine, but not a something special, too. Balanced action AK models, AEK or even AK12 SBR is a better blaster than this.

  • A bearded being from beyond ti

    Nice, thanks for the help!

  • Oliver BombDog

    My only complaint with these guns is that the screws that hold the hand guard on don’t stand up well. In the last couple of months I’ve seen two different M27s (USMCs 416) that have had part of the hand guard screw sheared off. And I’ve had them come loose while I was shooting aswell.