Tuesday, July 2, 2013

Sunday, H&K Sunday

I had a reader contact me last week about the conversion of Suomi drums to other 9mm firearms. I've gotten a degree of success in getting the drums to run in other weapons, but the Hi Point is still elusive. Out of 70-ish rounds, I still get 1-3 failures to feed. In an Uzi, a MAC, or an MP5, where there is a lot more room to work with in the mag, I have little to no trouble getting a reasonable feed. This reader wanted to know everything I knew about converting one for use with an Uzi, specifically a transferable machinegun. We did some story swapping and talking, and as it turned out, he was able to come visit the Redneck palace this last weekend.
Little did I know that he was bringing a ton of guns and ammunition, most of which were either NFA registered receivers or registered sears. I got to fire one of almost everything that H&K has ever made, including, but not limited to:
HK 11, 51,53,mp5, mp5k, mp5k reverse stretch, 23/21e, and two different 91's

There was also an AR15 with a DIAS , as well as a DLO Uzi and a Mac10 in .45acp, with a suppressed Lage upper. Aside from my carry piece, there was one other semi auto there, a Saiga 12. A Serbu Super Shorty made an appearance as well.
(Side note: if anyone ever hands you a H&K51 with a 50 round drum under it and an autosear, make sure you have a mouthguard in place, and earplugs under your outer hearing protection. A little suntan lotion wouldn't hurt, either. Jeebus, that was intense.)

The gentleman in question drove all the way from another state just to pick my brain and let me run some ammo through his MGs. I am still in awe of his immense generosity.

We spent Saturday working on a drum to see if we could get one of my designs to work in his gun, and we did indeed get one to cycle a full drum by hand in his gun simply by cycling the bolt (70 times!), so we knew we had something worth taking to the range and trying out.
At the range, it fed fine in semi auto, but the first time it was tried in FA, it had a couple of stoppages. These were due to friction, as we would later find out. I did some tinkering with the drum, loaded it all the way full, then did a complete drum dump (~70 rounds) in semi auto with no problems. Next, I tried it in FA, and had one stovepipe and two failures to feed, before I got about 65 rounds out of it in a row with no problem whatsoever. It ran and ran and ran. Even in full auto fire, I didn't think it was ever going to end.
Since it runs fine in semi, I believe friction kept it from keeping up with full auto feed rate. The owner of the Uzi took the drum home and is going to work on the friction issue, and maybe he'll come out with something worth making more of. I think he will, he's just got to get the bugs out.

 Anyway, enough talk. Let's look at machineguns, shall we?

 Here's the owner shooting his MP5k with a Vector drum under it
Me and a buddy shooting the MP5k

The AR15 with lightning link

The MP5K. I don't know the difference between this K and the last one I shot, except that the cyclic rate on this one is almost insane.

I believe this was a HK53

My all-time favorite of the day, the 51. MUST HAS NAO!

More of the 51

My friend shooting the Mac10 with Lage upper and can.

Shooting the MM11. This is just wrong. You don't put a gun like this in my hands and expect to take it back from me.

Shooting the 23e. THIS. IS. JUST. NOT. FAIR.

Shooting the same 23e, but with the bolt, feed tray, and barrel in for a 21. (In other words, going from .308 to 5.56 in a few seconds.)

I now know that the NFA34 was not drafted by a bunch of men wanting to reduce crime, but by a number of married women who were tired of their husbands bringing home new machineguns every day and sitting out in the back pasture shooting and ignoring the wives. There's just no way a woman can compete with a large machinegun collection until you either run out of ammo or something breaks.

A TON of gratitude goes out to my new-found-out-of-town friends Scott H. and Houston H.
I'm glad y'all tried to get in touch with me, and I hope we can/have come up with something functional with the drums for your Uzi.


  1. Wow, you have a good time there. :)
    So, what the "lightning link" is?

    1. Yup, really good time. =)

      A "lightning link" is a very small piece of metal that can be put in a normal semi auto AR 15 and convert it to full auto fire.
      Very simple piece of metal.

    2. Looks simple enough. Is it reliable more or less? I saw a stoppage at ar-15 video, was it ammo caused?

    3. Very reliable.
      Stoppage was a problem with magazine, cheap junk. =)

  2. Sounds like you had an enjoyable day. I'm glad you are starting to get the drum mag worked out. As for the friction, two possible suggestions. A slightly stiffer spring, maybe 2 or 3 pounds heavier and some graphite in the feed rails.

    1. 1. The spring was wound very tight, more than they are from the factory.
      2. He sprayed a bunch of graphite in the drum beforehand.

    2. Only thing I can think of is making a slightly longer stiffer spring. This is the flat wound spring right?

    3. The spring is contained in a metal spool. If you want more spring tension, you unbolt the follower arm and ratchet the clockspring however much more you like.
      The spring has a ton of tension on it now, the only solution at this point is to mount some PTFE delrin strips inside the drum to smooth out the travel of the rounds.