InRangeTV: HK416 Mud Test


InRangeTV did a mud rest on the HK416/MR556 and the rifle did not do very well. So this video it making it rounds on the gun forums and making some waves.

I’ve already seen people online say how the test is a fluke, means nothing, is unfair, etc. That a MR556 upper is not meant to be abused and its’ performance can not reflect the uber-reliability of a HK416. That mud doesn’t exist in real life shooting conditions. That if a shooter gets their weapon muddy they are negligent and deserve to die in a gun fight. Etc.

It is kinda interesting that InRangeTV has done this test with several direct impingement AR15s and they fared better. Tests like this often come down to the grit in the mud.

I’ve owned a few piston uppers for the AR15, LWRC and HK, and I don’t get how adding more moving parts, springs, and etc is suppose to make a gun more reliable. People claim pistons guns are cleaner, but you just end up having to scrape the carbon off the piston with a scraper tool. The same amount of crud, just in different locations.

InRangeTV speculates that the gases being blow into the receiver and bolt carrier help blow out contaminants from the standard AR15 action helping increase reliability in these mud test. What detractors of the AR15 often refer to as “shitting where it eats”.

I’m not saying pistons guns are bad. Personally, I decided if I wanted a piston gun, I’d rather buy a gun designed from the ground up for use with a piston. A SCAR, SIG, AK, etc. I own an AK and a Sig MCX. I wouldn’t say no to a SCAR, B&T APC rifle, etc.

Ultimately tests like this one can be very random. Success or failure can come down to if a little piece of grit manages to get into an area where it will prevent function. Some guns, like the AK, tend to fail tests with larger grit because the opening for the safety and bolt handle allow for larger chunks of rocks, grit, and debris to get into places where it can stop the functioning of the gun. The AR has less openings for large grit to get in. But small grit in liquid can settle into places that cause problems.

I remember seeing one of my fellow recruits in boot camp being unable to open the action on his issue M16A2 after we went though a portion of the crucible. In this event, we were having to submerse our selves completely in muddy water to pass though various obstacles. I had my buttpack completely fill with mud and it felt like it weight a ton and I got to overhear the instructors point me out make fun of me because of it. In the case of the other recruit, there was so much silt mud sediment that was carried in the watery mud he crawled though that it filled his receiver extension behind the buffer. After he exited the muddy water, the liquid drained from his rifle, leaving the buffer tube full of dirt. This preventing the action from being able to be opened. He ended up having to field strip his rifle, and use a cleaning rod to break up all the sediment that was in his buffer tube.

Shit happens.

I don’t really mean to defend HK, and I sure plan to reference this video when I tease HK fans. But I have one last rebuttal for them. I saw several people try and defend the HK416 by saying, “but it is used by militaries around the world because it is the best”. Let me remind them that many counties want M4 Carbines and similar, but many of these countries don’t want to be buying weapons from us Ugly Americans. Prior to the HK416/417, most of these groups bought the Canadian C7/C8 firearms so that they could have ARs with out buying American guns. Then they bought HKs. Now, years after HK AR pattern rifles, we see some of these groups buy stuff like the SIG516 or SIG MCX. They can have their cake, with out it being American.


  1. My understanding is that the only benefits of piston guns is with short barrels and suppressors. I could be wrong but that’s what I’ve heard. I agree on the preference for a gun designed around a piston not adapted to one. Not sure if 416s have carrier tilt issues like the others.

  2. After I learned more about the M-16/AR-15, I came to a couple of conclusions:

    1. The only benefit of a “piston gun” is that you don’t have the gas tube as long as it is on the M-16.
    2. The M-16/AR-15 is a “piston gun,” it is just that the piston is behind the bolt head, and the cylinder is the bolt carrier.
    3. This quest for the ultimate in reliability in a semi-auto/full-auto rifle can be cured only by going to a bolt-action rifle. If you want the ultimate in rifle reliability, you need to get rid of any gas system, period. You could clog the buffer tube, per the above. You could plug up the gas port. You could fill up the gas cylinder (eg, on a Garand or M14). You could bend the op-rod (again, Garand/M14 issue). You could have a bore obstruction that causes a spent case to lodge in the chamber so well that the gas system cannot extract it – I’ve seen that on a Garand, and the op-rod was bent as well as the case head was ripped off.

    Want to avoid all of those failure modes? Go get a Mauser or 1903 (which is basically a small-ring Mauser).

  3. “Prior to the HK416/417, most of these groups bought the Canadian C7/C8 firearms so that they could have ARs with out buying American guns.”

    That and Colt Canada ARs are better. HK is also one of the few European manufacturers set up to equip armies. Well, FN is but I believe their contract wouldn’t allow them to sell DI guns built on the US TDP to other European nations.

  4. The main reason that the Canadian product was chosen for many of those army’s procurement…? Blame the antiquated TDP that Colt was offering. Diemaco had CHF barrels from the git-go, and those were the primary reasons that the Dutch and the Danes preferred those. Colt also had quality-control issues that Diemaco did not–From what I’ve heard, the Colt-manufactured weapons that showed up for testing were basically afterthoughts, because Colt didn’t care to put much effort into the whole thing, figuring that they had the bidding sewn up. Diemaco put more effort into their submissions, and it showed. They were also more flexible about options, and their variation of the M16 was preferred over what Colt offered up.

    Colt can do really good work; their problem is consistency. Also, at the time of the bidding for the Dutch and Danish contracts, Colt was flush with cash from the M4 program, had plenty of business, and didn’t have a problem letting Diemaco sell. Later on, they bought up Diemaco, creating Colt Canada.

    Having handled the Diemaco product while training with the Canadians, I found them to be very nice, well-made, and pretty damn accurate. About as good as the FN M16A2 I had that was a tack-driver, TBH.


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