H&K 21 General Purpose Machine Gun


Over the weekend   we were able to shoot the HK21 purchased by my friend, a Class 3 dealer.  The HK21 is  a belt fed  light machine-gun based off the G3 rifle made by H&K firing 7.62mm NATO.  It’s been around since 1961 and has seen considerable use in various world armed forces.  One stand out reported use was by US Army Delta Force.  In the past I have even seen pictures of it being fired in Iraq by US Forces at a firing range.

Having fired the full auto G3 several time over the last few years I was a little surprised by just how rough the 21 was.  It has considerable recoil.  While heavier than the G3, the cyclic rate much higher and it is a brute.

I was able to get some hurried video when firing the gun the first day. You can watch below.


on the video below you can see the cross pin that holds the gopro camera in the head mount was vibrated out by the recoil of the gun

Last video.  I did try to stand up and hold the gun with one hand  i.e. Rambo but sad to say the belt kinked on me and it didn’t make for a very compelling video.  Next time I will try with a shorter belt.

Sad to say I did not have time for any kind of accuracy test.  I will have to think up some method to test out its “accuracy” while fired in busts and  semi auto in the future.  I think I still have some of the US Army reduced range machine gun targets.

The gun is a fun. I doubt you needed to be told that though.   It is rough however and there is technique to firing it prone so as not to ruin your shoulder and give yourself a headache.     As a GPMG the gun does have a quick change barrel that i forgot to video a demonstration of.   In coming weeks I will try to attempt a longer instructional video on the weapon for anyone interested.  Comment below if you want to see something like that.  I personally always  worry that videos like that appear as “showing off”  or a “look what I get to play with and you  never will” kind of things.   I wish everyone could own and use MGs etc as a normal part of gun ownership. For those that can’t I  hope maybe to at least  answer questions about it and not  play it up as the ULTIMATE!! experience.

A  class 3  M60 and a STG 44 will be arriving in the next few months and I will do my best to get more entertaining videos of those for everyone.


  1. Thanks for the post, Shawn. Do you have any thoughts on what made it so rough to shoot? Was it just the (relatively) light weight of the thing?

  2. The older 21 (as opposed to the 21E) doesn’t have the large extended buffer which goes back into the stock. The larger buffer greatly reduces the felt recoil. You have to keep an eye on non E guns since they can beat themselves to death.

    Accuracy on the 21/21E is phenomenal. It’s one of the only machine guns with a true free float barrel. The 21E was popular with Delta because it could be used with a variable powered optic as a DMR, yet still have the capability for sustained fire when needed.

    As an owner of a US made clone of the 23E (5.56mm), I can tell you it’s a ton of fun to shoot in full auto. Just don’t buy one from Michael’s Machines.

    • Thanks for some background information Will. I am not the biggest HK fan so my knowledge on most of their stuff is not broad. the one Im using in the video is an early model. And it does all it can to give you a headache. I would have much rather be shooting a 556 model.

      If you have some video you would like to share, I would love to add it to my post as a comparison. And if you want to write about your gun or the 21 I would like to post it here. Invite is always open

      • Shawn,

        I appreciate the invitation! I may take you up on it, time permitting. I have checked your page regularly ever since Hognose recommended it, years ago.

        I don’t have too many videos. This is relatively recent, though (sorry for the orientation, I didn’t film it). In 23e configuration it’s possible to shoot it offhand, although it’s still heavy. I think mine weighs about 22 lbs unloaded with the kahles k16i on top. The accuracy is incredible. Prone you can land all 3 rounds of a burst on E types at 200 yards. Cyclic rate is about 850 rounds per minute, but it depends on the ammo. 5.56 pressure cycles a little faster than .223.


        • That is awesome man. I can tell you for sure after seeing that , I would much rather have been shooting your gun. I definitely hope we keep hearing from you.


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