Dealing With HK416 Bolt Over Base Malfunctions

In my opinion, the HK416 is not a good carbine. This is primarily due to its increased weight and recoil compared to the standard M4. The increased recoil, due to greater reciprocating mass and velocity, also increases the probability of damaged or loosened components. Furthermore, the already high cyclic rate of the 416 is increased further by the attachment of a silencer. As you can see in this video, the cyclic rate is simply too fast for even one of the strongest magazine springs on the market, the Lancer L5 AWM, to keep up with – resulting in a bolt-over-base malfunction (the rear of the case has not risen to the top of the magazine before the bolt face has returned to push a new round into the chamber). This is not an isolated incident, but a common occurrence with the multiple 416s I have witnessed exhibiting this problem.

If you are part of a unit or organization which must use the HK416, the best upgrade (short of replacing the entire weapon) would be to replace the receiver extension tube and buffer assembly with the Vltor A5 system (specifically the A5H4). Vltor tested the HK416 with the A5 and saw a reduction in cyclic rate from 1106 rounds per minute (stock, suppressed) to 973 rounds per minute (A5H4, suppressed).

If you cannot replace the receiver extension tube with the A5 system or get rid of the HK416s entirely, try using a Tactical Springs LLC/Springco “Red” action spring along with an H3 or heavier buffer.

33 comments

  • Or, just use GEN M3 PMAGS. You’re over thinking it. Yes, they run fast. A strong spring isn’t necessarily what’s needed to keep up with high cyclic rates. We’ve run about 30k rounds through 14.5 and the shorties, and thousands of those suppressed. Works just fine like it comes from Oberndorf.

    • Good to know. I haven’t seen that sort of reliability with 416s and EMags, but I haven’t used Gen 3s with anything.

    • Ha ha ha…my Colt 6920 will work with ANY magazine i put in it.

      • TrollipopLollipop

        ^depends on how often you’ve cleaned it tho haha

        • You mean like a simple 5 minute wipe down….Man that was tough.

          If you honestly feel any gun can do a day without cleaning over in Afghanistan you are horribly misled.

          • I went about a week between cleanings of the M4 in Iraq. My SAW needed a lot more maintenance than my M4. That one was cleaned every other day or so.

          • You sir are a brave man, I cleaned mine daily but again it was as simple as pulling the bcg out and wiping it down with a rag and putting some lubricant on it.

            Was it needed? I’m not sure but it never once failed me. Only issues I had were mags and ammo.

        • You mean the 5 minutes it takes every 1000 rounds? Field strip the gun and bolt carrier group. Douse everything in Fireclean. Run a wet patch of Fireclean down the bore. Go get a cup of coffee…come back. Wipe everything down, run a few more patches down the bore. Carbon from a DI gun is a lot easier to remove then carbon from a piston gun. From what I have seen carbon from a piston gun essentially bakes on due to Bernoulli’s law…hence all the scraping tools becoming available for cleaning piston guns.

          Weight, hard carbon, broken pistons, cycling issues, broken disconnectors, broken trigger and hammer pins. I will stick with a DI gun. If I really want to run a piston/AR-18 system I would just go with a SCAR or Beretta ARX-160.

  • Interesting to hear. This article from Canipe has quite a different take on the reliability. 67,000 with >20 malfunctions that the author attributed to magazine/ammo related. What do you think?

    http://soldiersystems.net/2013/03/30/canipe-correspondence-retiring-my-416/

  • Emags have been the standard for certain places that issue the 416 for a long time. It’s geometry, material, and design. There’s another place that runs quite a few of them on USGI green follower mags. Might want to look at the feeding device. :-)

    • This was the first time I had seen it with a Lancer. All of the others have been USGI or EMag.

  • Didn’t HK claim the 416 didn’t have a major increase in cyclic rate when shooting suppressed?

    It may also be that I’m unobservant: the MR556 I shot seemed very smoothe and had low recoil.

    What configurations of 416 have you been shooting?

  • “Due diligence”, Dude

  • “Due diligence”

  • HK416A5, latest version of HK416, has gas regulator specifically designed for suppressed fire. What version of HK416 did you shoot, Andrew?

  • Andrew all weapons have there ups and downs but the HK416A5 or the HK416 are the best of the best in combat , they got there problems but they can be work , imagine AK47 one or the best weapons in the market and the choice of many military personnel around the world and sometimes you have problems with them . You work the way around and make the weapon work , so I think its the same for the HK weapons you got to work youre way around them…..

    • To say the HK416 is the “best of the best in combat” is quite a statement without data backing it up. You can’t say that about a firearm that has only been in the field for a relatively short amount of time.

      • TrollipopLollipop

        The HK416 is as battle proven as the SCAR and Tavor; they’ve seen plenty of combat, not as much as the vaunted AK, but plenty enough that they’re in the arsenals of several spec ops groups, not to mention entire armies in some cases. I doubt anyone who is serious would claim that the HK416, the rifle used to gun down Osama Bin Laden, is not battle proven enough.

        • You mean the HK416 that is in use by only 2 groups in the US? The one that has horribly mixed reviews by the Norwegian army, one unit even had a couple of soldiers die when their HK416′s locked up.

          The SCAR has its issues as well, though most will never be spoke about due to testers still being held to NDA’s to this day, but there is a reason after we were issued them that they took them back and gave us our M4A1′s back and its not a money issue. There is a reason the HK416 has not seen wide spread use, it was adopted back before the CQBR and MK18 really came out, by the time they had the fleas worked out of those the HK416 was a full fleeted system in those two units, with spare parts and everything. Even though its more expensive, and works about as good as the CQBR and has similar parts life its easier to keep those running than replacing everything they have again.

          The Tavor also has a lot of issues, its partly why the X95 is replacing the Tavors they have.

          • That statement is just false Joshua. No Norwegian soldiers have died because of their 416s locked up. During the 2nd of May (2010) TIC, the AAR provided info that the weapons had NO lubrication, no maintenance or cleaning and were fired with (non approved) suppressors. No Norwegians died in that TIC, but there were 9 injuries. 2 of them died a few weeks later to an IED.
            That unit had previously used (and still used to some extent) the HK G36KV.

            The problems Norway have had with their 416s are all because of improper maintenance, bad (lead-free) ammo and a few pins in the wrong dimensions.

          • Thanks for the clarification, my friend who is a Norwegian soldier is the one who told me about it, looks like his info was a bit off.

            Sounds like the issues faced with the HK416 are the same as we see with idiots and their M4′s.

          • You could read this as well:
            http://www.lightfighter.net/topic/a-norwegian-perspective-on-the-hk416-feedback-upgrade-and-some-range-work

            It’s like the issues you have with anything, it sucks if you do it wrong.

        • You need to realize that our Tier 1 groups that use the HK416 go through guns like water. The HK416 that are modified by Crane/CAG run well surpressed and can handle a lot of full auto. Those guns get rebuilt and replaced on a very regular basis. I don’t think big army has the logistics or the resources to fully support a finicky weapon like the HK416. The M4 carbine is caveman simple. Replace gas rings, buffer spring, extractor and extractor spring every 4 thousand rounds and run that gun wet. (Ironically on a piston gun you are going to be replacing buffer spring, extractor and extractor spring every 4 thousand rounds also….but being a piston gun you have to worry about carrier tilt, broken discos, broken bolts, bent trigger and hammer pins…but hey you no longer have gas rings to worry about!!!) Use good magazines and the gun will run just about as good as anything out there.

  • How can a cyclic rate that high be good for reliability? I am finding non-suppressed rate of 850 rounds per minute. Seems high.

  • I have used 416′s a ton. I have had zero bolt over malfunctions shooting auto unsuppressed, granted that shooting auto is about 2% of the rounds I have fired through a 416. I have done a mag dump with a surefire 60 round mag without issue as several 30 rnd bills drills.

    I think overall the 416 is pretty reliable, depending on configuration. I have mostly used usgi type mags and emags. All of the HK mags we had were pulled due to constant failure and most would not lock the bolt to the rear after the last round.

    The issues with the 416 for me were always weight, heat, bulk and a few other little quirks. The quad rail on those things is massive, heats up insanely fast, and comes loose constantly. The bolt that holds it on is set up to use the lug from the bolt in your rifle so it can be removed in the field, but it make just about any screwdriver worthless and I am not too keen on wrenching the shit out of it with one of the most failure prone and important parts of my rifle. Result? Most of the rails come loose while firing even with loc-tite.

    The flip up front sight is worthless and eats muzzle blast the whole time until it falls off, horrible design there. The rear HK sights also suck, but those are easily replaceable.

    On early models we would often see broken trigger/hammer pins and broken disconnectors, not sure if they fixed this or not. I do know for a lot of people it is hard to get parts for these things. Keep in mind these are guns that were getting a little far in their service life w/ little maintenance.

    The emags when they wear out can be over-inserted into the gun and the bolt won’t go home. Like the mags, but not sure if they are the best option as this can be a pretty bad malfunction depending on how and where it happens.

    Also, I won’t say a number because I don’t have it in front of me, but the bbl life on these (as stated from HK) is pretty low.

    • Barrel and bolt life are currently 10,000 rounds as rated by HK. The HK416 also features a CHF barrel and a bolt steel equal to Carpenter Aermet(but not made by Carpenter) which is 2.5x stronger than C158 steel.

      Interestingly that is what the M4A1 gets on its bolt/barrel. The M4 uses a non CHF barrel and a C158 bolt.

      At the same time the HK416 is nearly three times the price of a M4A1 in .gov contracts. M4A1($657) HK416($1,800-$2,000).

  • My only real experiemce with the 416 was a 600 round IAR fam fire, all in full auto. I was the third shooter, and there were multiple shooters on the line. To the guns credit, it kept on chugging along, though quite hot. I did witness multiple instances of the gun outrunning the mags, noteably the ones woth the green and black followers. I did try a shaved down gen 2 pmag for a 30 round dump and it worked flawlessly (this was pre gen 3).

    While the rifle is nice I see nothing justifying the cost over a good m4, and view it as an awkward replacement for thr SAW. Our IAR gunners were expected to carry 22 mags, and most did not have the new orange followers. Semper gumby.

    Mike

  • HK416 came to existence because the delta force reached out to HK frustrated with Colt’s inability to properly address the issues M4s were having in, I believe, around 2002. The cost of ownership for HK416 is probably lower than that of M4.

    See this:
    http://ingunowners.com/forums/long-guns/153349-scar-16-17-hk-mr556.html

  • Chuck that is not why Delta went to HK for the HK416. They were very happy with their M4′s at the time but wanted a rifle that was as compact as the MP5 but offered the ballistics of the M4.

    At the time the only experience with short barreled AR-15′s was the Car-15, but its setup was not ideal either and it was not as reliable as they wanted, so after one member visited HK and saw their idea of a 10″ AR they got together and worked on making the HK416.

    Then in 2003 Colt and CRANE began work on the 10.3″ MK18 after a few years of testing and shortly after the adoption of the HK416, the MK18/M4 CQBR became the standard SBR.

    After numerous tests CRANE found that they could increase the parts life and reliability of the M4A1 and CQBR/Mk18 even further by free floating the barrel, thus we have the RIS II.

    There is a reason why there are only 2 groups who still use the HK416 in the US, oddly enough it is the 2 groups who first adopted and made it a full fleeted system.

  • Chuck that is not why Delta went to HK for the HK416. They were very happy with their M4′s at the time but wanted a rifle that was as compact as the MP5 but offered the ballistics of the M4.

    At the time the only experience with short barreled AR-15′s was the Car-15, but its setup was not ideal either and it was not as reliable as they wanted, so after one member visited HK and saw their idea of a 10″ AR they got together and worked on making the HK416.

    Then in 2003 Colt and CRANE began work on the 10.3″ MK18 after a few years of testing and shortly after the adoption of the HK416, the MK18/M4 CQBR became the standard SBR.

    After numerous tests CRANE found that they could increase the parts life and reliability of the M4A1 and CQBR/Mk18 even further by free floating the barrel, thus we have the RIS II.

    There is a reason why there are only 2 groups who still use the HK416 in the US, oddly enough it is the 2 groups who first adopted and made it a full fleeted system.

  • Got it. Thanks for your feedback Joshua.

  • Andrew -

    do you still have the high speed video that shows a comparison of a 416 and a DI weapon? Barrel flex on the 416 is atrocious. Most won’t believe it until they see it.

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