Anybody got one? Any thoughts on the “new” one the A4? It’s the first iteration that I really like.

Obviously I can’t ask opinions and tell you what to say but here goes. I would like actual experience you guys have or opinions EXCEPT for listening to you guys say you could buy 2 or 3 of whatever else you like. Yes, it is crazy HK pricing. Got it.

I want real world stuff because I’m seriously tempted by this one.

I also am intrigued by the Gate Lock system of attaching cans on A2 flashhiders. Anybody ever use these?

I was tempted by the piston LWRC pistol braced version sbr but that was 2600 which is cheaper but not exactly cheap. So, what’s the hive mind think? (except for price lol)

Thanks.

I have one, although it’s a Form 1 pistol because the factory SBRs weren’t yet a thing a year ago when I bought it. Compared to the old MR556A1, it’s a nice improvement, with a full ambi lower, ambi extended charging handle, 45 degree selector, lighter profile barrel, AGB, and M-lok handguard. In general terms, it’s very accurate and not bad on weight (although being a piston AR, it isn’t going to be as light as a similar length DI AR). One big controversy is that it doesn’t come with a chrome lined barrel like the German guns, but that doesn’t bother me as the steel has a higher chromium content than typical AR barrels, plus HK says they’ll replace it if it ever wears out. The AGB is only two positions, but it seems to work best with low backpressure suppressors since it’s a bit over gassed. It can be tuned by replacing the vent gas screw, that HK sells in a bunch of different sizes. I’m happy with the factory trigger, although it’s not quite as nice as a Geissele trigger, it’s still pretty crisp and fairly light. You can change out the trigger for most AR pattern triggers, but note that you’ll have to change the safety axle to get it to work with standard AR triggers. Also, you’ll lose the ability to put the gun on safe with the hammer down.

Regarding gate-lok suppressors, I have a Griffin adapter, but haven’t used it. Since they don’t recommend using crush washers with suppressor mounts, I usually just swap out the muzzle device for a proper mount since I have to take it off to remove the crush washer anyway. Plus, almost all of my cans are set up for taper mount. That said, the MR556 comes with an A1 type flash hider that doesn’t use a washer since it doesn’t need to be timed, so it’s probably OK as is.

Obligatory photo.



Feel free to ask any other questions.

This message has been edited. Last edited by: Dwill104,

It doesn’t come with irons. I see yours bit aren’t sure exactly what they are. Do you like them, would you go a different direction?

I was thinking the gate lock setup and an alignment rod would make a whole bunch of my AR’s can ready without dripping a grand on half a dozen muzzle devices.

My understanding is they they don’t recommend crush washers unless you verify concentricity which I thought an alignment rod would do. Is that about right?

Yours looks pretty identical other than the MD. It sure felt handy in the store. I thought it would be heavier.

The sights are flip-up HK factory sights. They’re nice sights and co-witness with my Eotech, but they are quite expensive, as is most everything HK.

Yeah, if you verify with an alignment rod, it should be OK. In any case, the MR doesn’t use a crush washer and it’s flash hider indexes on the barrel shoulder.

For other small differences from the factory setup, the QD point in the stock doesn’t come with it, and my hand guard is the QD version, which is slightly shorter and doesn’t require a tool to remove. I also replaced the right side safety lever with the A5 safety, which is slightly shorter and higher so there is more clearance from the top of my hand.

No experience with the MR556. Have a considerable amount of time on the 416 version. It’s a great toy. It’s heavy, lots of proprietary parts, and has a “clunky” recoil impulse. The one I had was still fairly gassy with a Surefire RC2 mounted on it.

Given the choice between the MR556/416 and a 11.5 MK18 pattern gun, I’d go with the DI gun hands down.

My son has the DD Mk 18. Nice gun. The HK just speaks to me. If I buy this it isn’t because it’s a brilliant choice it will be a massive “I want this” moment unless somebody talks me out of it.

I like the HK cache, I do like the mlok rail better, I don’t like the extra 1500 bucks. lol.

As for gassy I keep reading the key there is a low back pressure can and then it’s not gassy at all. I was leaning towards a Silencerco velos (sp?). Any input there?

The Velos is a Charlie mount, so it’s not really an optimum choice if you want to use a gate-lock mount. You’ll have to use an adapter for anything except Charlie/ASR muzzle devices.

Yea you are right. The salesman was showing me the Velos and a muzzle device. I confused that in my head. Now I forget the can that had the Hub (?) mount. I own one can and it’s a direct thread 22 can I’ve had forever. This stuff is confusing to me.

quote:

Originally posted by pedropcola:
Yea you are right. The salesman was showing me the Velos and a muzzle device. I confused that in my head. Now I forget the can that had the Hub (?) mount. I own one can and it’s a direct thread 22 can I’ve had forever. This stuff is confusing to me.

Fortunately, things aren’t as limiting as they used to be. Almost all newer cans are HUB, and you can get adapters for most of the few that aren’t. ECCO machine makes an adapter that converts Charlie cans to Bravo (HUB) if you’re set on the Velos. About the only truly proprietary cans are many of the Huxwrk cans that can only use their mounts.

What do you want to do? If the number one priority is to use the A1/A2 AR flash hider, then your options are to get one of the Griffin Gate Lok can, or another can that supports those flash hiders. Or Griffin makes a Gate Lok HUB adapter, so you can use any Bravo threaded suppressor.

If you’re open to changing muzzle devices, everything is an option.

This is where I get into trouble. Swapping half a dozen muzzle devices does not sound like fun which is why the Gate Lock stuff sounded so appealing. Ugh. It’s research time unfortunately.

Not, the MR but the 416A5. Lot of time with it and never had any issues. Runs great and accurate for a 11.5" barrel. We use B&T Rotex cans mounted on the A2 FHs.

quote:

Originally posted by rbdub474:
...accurate for a 11.5" barrel.

In my experience, shorter AR barrels don't necessarily produce lower accuracy than longer AR barrels -- at least to short-ish distances of 100 to 200 yards. Accuracy for 300+ yards targets is a different matter. At longer ranges the lower muzzle velocity definitely increases horizontal bullet drift from crosswinds. There seems to be something that results in higher vertical dispersion from a shorter barrel, but I really don't know what it is. Of course the shorter barrel's lower MV means the bullet drops to transonic speed sooner, which really affects accuracy negatively.

I have a couple of buddies who built ARs with 11" barrels for 2-rifle matches. They used top of the line barrel blanks -- Bartlein, Krieger. These ARs are capable of consistent 3/4 MOA or better at 100 yards. Not quite up to the 1/2 MOA that is possible with some 18-20" Bartleins & Kriegers, but pretty close. IMO accuracy is more dependent on the quality of the barrel blank, the way the barrel is chambered, and the ammo. And, as always, the capabilities of the shooter.

Ok. I bought it. They only had one and I am weak. The wait begins. Hopefully fairly short.