Place holder for pictures. My kit arrives tomorrow. Interested in seeing the comm condition of these when they show up…and I’m surprised we haven’t seen any pictures aside from dealer photos so far.

ETA…here.

HK carrier and Bolt (a little rough)
Clean cut around the trunnion
Looks like everything is there except one roller out of the bolt



I think I’ll be welding a picatinny rail into this one…

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I have a buddy that bought a few.  

He's good at building HK's.  I expect he'll have one up and running soon.  


This one was NoHair's (different buddy, and the OG HK bender).   RIP NoHair.

I’m in for watching the process of these getting built.

Mine just showed up a few minutes ago. Well worn but nothing looks unserviceable. The trunion was cut rather nicely compared to some of the pics I've been seeing. Barely scored. Both bolt and carrier are HK. The bolt definitely has some miles on it but no real damage. I'm pretty happy with it. Most of the parts will look like new when refinished.

ETA: Anyone ever seen a print or dimensions for one of these barrels? I'll be getting some from RCM whenever they are available but I'd really like to get this thing built before winter.

RCM barrels expected Sept/Oct

Elkaholic on HKP?

Yup.

Does he build HKs as a side hustle?

Alright!  I’ll shoot you a message about dimensions once I get the kit and take a look. You’re lucky to have what you do on hand. I’m over here hoping I don’t F up a $1600 parts kit…haha.

Are you going to try building yourself?

Yes. I have a tig welder, lathe, and mill. I’ll assess it once the kit arrives and go from there. Pretty sure I can finish it out as long as I take my time. Turned this into this….


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That’s amazing work!

Nice work. What is that from?

It’s a VZ61 receiver. Theyre fun little guns

My one kit was pretty good other then a deep cut trunion that century is replacing.  Century had me a return label for the reunion/forearm section same day.

My other kit from Apex was trashed.  The carrier is cracked in several places.  The ejector lever end is broken off.  Cocking tube support is cracked.  Bolt head is crap.  Apex said the would replace those parts but still waiting on a RMA.

I have seen pics from some kits they look fantastic, seen some that look pretty meh.

Good thread on HK pro.

No.  He just builds stuff for himself.

Dang…okay. I question whether apex was a mistake and if century kept the nicer stuff for themselves.

I think this is NoHair's gun.

My crack gun dealer / SOT shooting.

I love how it rattles the ear pro right off of him.

Sigh Id really like one of those kits to build but they come at a point in my life where its just not quite feasible

Wish they had these yesteryear

I love how those links are absolutely launching lol.

Mine popped up in the mail today…

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Can you put the A3 stocks on these?

Apex kit came in. It seems to be in OK shape. Attached File
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Not without some extra work and omitting the receiver reinforcing rails.

Jesus bro…I thought mine was nice. You hit the lottery…

The trunnion is scraped up on the receiver side. I assume the reciever is to be welded, so maybe it's no big deal.
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That looks fine. The only jacked up trunnions ive seen are the ones with deep band saw cut.  I’ll trade ya if that bothers you…🤣

Yeah there are pics on the HK forum of a trunion that was pretty much destroyed. They cut about a 1/4” down into it.  I don’t think you’ll have any problem at all with that one. Once it’s rewelded, you won’t be able to tell.

Yup. You’ll have to chuck it up in a lathe and clean it up before you press the trunnion out anyways…and then chuck it up again to get the old receiver bits and welds off anyhow.

Part of me kind of wonders if I couldn't just leave the trunion in there and weld the whole thing to the new receiver. I'm sure there is some reason it is done that way that would probably be obvious once I'm into it.

I’d rather have the receiver welded to the trunnion properly with oroginal metal than try to graft a receiver into the old trunnion welds. I’m sure it would work fine if the welds are done correctly, but it’s not that much more work to do it correctly.

Yeah I was going to start cleaning it up per the ORF pictorial at WG but then got that thought in my head. I’m pretty sure I can get it cleaned up just fine without taking it out but maybe it’s tougher to get to the welds like that.

I was just thinking it would pretty well guarantee the shroud aligns with the barrel.

Are any of you guys bending flats yourself? I need to get that part sorted out before I get too far along.

I’ve seen quite a few different setups but really no decent plans for the HKParts type jig. I’d kinda like to build my own so maybe that will keep me busy while some of you other guys sort out how to graft in the feed box.

Bending my own. Going with a 3D printed jig.

Don’t let me stop you. I’ve never built one and this is my first rodeo. Worth asking on HK Pro or Weapons Guild.

I aint worried, I posted just for reference for others on the kit I got. I was happy enough with it I ordered a second kit.

I've been trying to find one of those 3D printed jigs.  Do you know where to get one?

I am trying my hand making a few G3 kits. I figure if I can turn a few of those out with good results, I might get the confidence try these. Im using the HKParts jig. I would like to find one of their straightening mandrels, but neither them nor RTG has them listed. My receivers need some tweaking to get the carrier to fall through easily.

I am on the fence to get a kit.  I have so many projects and I have never built up a belt fed anything before.

How much more difficult is this going to be than a G3 Build?

I seem to recall the ones made by the popular HK smiths in the 80s/90s were having to be sent back for repairs on regular occasion but that was literally decades ago and going by failing memory.

I'm in.

I was debating on this, only because I have other priorities right now. But I just saw that both Atlantic and Apex sold out of the kits, and didn't want to miss out so I snagged a kit from Centerfire Systems. It says "preorder" so hopefully there are no shenanigans receiving it.

If they jerk you around, Century Arms (the original importer) still had them at the same price last I looked.

Thanks, damn I wish I knew that. Well I'll keep that in mind if it the need arises. Hopefully Centerfire Systems delivers.

I was on the fence myself on one of these kits.

I have built multiple HK style roller-delayed guns and have all of the receiver alignment welding jigs, flat bending jigs, mandrels, letc. to do it.

My experience is that just rolling a flat doesn't get you a really "round" receiver.  You really need the internal receiver mandrel and external rail and rib dies to finish forming the receiver if you want something that is close to round and spec.  For a mag fed build maybe an out of round works but for a belt fed build I would be pretty concerned about trying to weld the feed mech box to anything that isn't close to perfectly round and formed right.

Even though I have all of the receiver jigs to roll flats if I was to attempt this I would personally just buy a PTR receiver to start as they will be better than anything I could do even with all the receiver jigs/mandrels and the PTR receiver are so cheap compared to the cost of the total build.

My other concern is that these kits look like they have a lot of mileage and I question whether they will achieve bolt gap on what look like really high mileage bolts. Unlike a fixed barrel build where you can press and pin the barrel to meet bolt gap on any bolt head, the beltfed guns you really can't do much of anything about how deep the barrel seats and the bolt gap that ensues other than stuff ever larger rollers in the bolt head.

Some of the kits look like they have a lot of corrosion on them which may make getting clean TIG welds difficult, even if you spend a bunch of time with navy jelly and a wire brush they may still not weld very clean.  Not saying it can't be done but fuck it looks like a lot of work to clean up these parts so they will weld  clean.  After building a couple guns from kits its so much easier to weld new clean parts vs. old partially corroded surplus parts in my experience.

I would think to do this right you would also need to make  specific weld heat sinks to keep everything in line with the belt box and prevent any weld through distortion on the back side of the receiver and/or warping similar to when you weld on a cocking tube, rear sight base, or weld over and remark a receiver model.

The other issue for me is that I don't have a reference old style model 21 to model the build against.  Whenever I have built guns in the past I have heavily relied upon a reference German gun for critical dimensions.  I feel like i would probably just really be winging it without some sort of functional reference gun to model after.

That said I have always wanted a HK51B and one of these kits may be the ticket to one of those builds in the future.

Either way it will be cool to see the result of what folks can do with these kits both on paid builds as well as home built guns.

That was mine!  Got the replacement today it's perfect.

Anyone still wanting, can't go wrong with century, no tax and free shipping.

Awesome. Glad to hear that. Kind of an expensive kit to get hosed like that on.

Here is a carrier from another kit, also being replaced.  You can see it's also cracked the length of the weld....gonna call that not serviceable

So far apex and century have both been cool about replacing clearly unserviceable parts.

I think I'm going to try and make my own straightening mandrel. I've got some prints for the receiver and found some for the mandrel over at WG. It sounds like most builders are using foil tape on an old bolt anymore. I think I'm going to try and make one that also aligns the components and will maybe work as a heatsink/backup for welding. Machining the tapered grooves for the rails with enough accuracy to do it's intended job might be a challenge with what I'm working with but I'm going to give it a shot.

I have some material ordered and a decent idea of how I'm going to make the bending jig now. I decided I have enough of these receivers to build that I can probably justify a proper setup to bend them with.

I saw that one. I got a brand new carrier from HK a long time ago that was cracked like that. Well cracked like that after the first time shooting it, and it was just an MP5. I'm glad to hear they are replacing these components without too much fuss.

From your pic the bolt head looks like it has pretty bad roller dents in the front roller pocket as well.   I am not sure if Century can do anything about that as all these kits look well used but just keep that in mind when you build it might not make bolt gap without some + sized rollers and/or you may need a new bolt head.