So during the preelection rush I ended up purchasing a Z43P from MKE/Zenith after a Z5RS with the intent to SBR both of them. I had mapped out my plans on what to add/change for the Z5 but not for the Z43P. I haven't seen a lot of posts here or "there" about how folks are setting these up. Any and all advice would be appreciated from folks who own these firearms. I totally admit it was an impulse buy and don't know much about what it's cloned after, ammo it likes, change ability with actual HK parts, etc.

I've gone down the SBR road with mine and it can be a little tricky for a couple of reasons I'll get into.



To clear out the low hanging fruit questions first, the Z43P is a clone of the HK33K with two major variances. First, it has a slightly shorter barrel and it doesn't use the HK33 sight tower design (it uses an MP5 style sight tower). Second it uses a proprietary Turk cocking handle, cocking tube support and cocking tube. The Z43P design is derivative of the HK21/23 machine gun, and it differs from the factory HK33/93 parts by way of a welded latch inside the cocking tube channel that the cocking handle cams onto when it closes. This design change means that two different tabs hold the cocking handle "closed"... these two tabs also mean that no HK parts will interchange with the assembly, so you are stuck with the Turk parts here unless Zenith releases US made parts as is rumored.

As for ammo, I've only shot PTac 62gr green tip through mine and it has run flawlessly. The gun is tremendously overcharged / oversprung like any HK rifle and it throws brass into low earth orbit. I imagine it would feed and fire just about anything, and with the 1/7 barrel I would assume it would have decent enough accuracy. With the 62gr green tip mine is a tack driver.

Now comes the hard part... SBRing and 922r parts compliance.

There are sadly very few HK33/93 compliance parts on the market, and you will be hard pressed to find some of them if you go down certain paths. Unlike the 9mm guns the Z43P requires one additional compliance part for a total of 7 instead of 6.

The parts I chose for my gun are:

- US made flash hider
- US made (PTR) buttstock body
- US made trigger
- US made disconnector
- US made hammer
- US made trigger box
- US made (RCM) bolt head assembly

I chose these parts because I wanted to use a real German handguard and a real German SEF trigger housing. US made SEF trigger housings are available, and if you are lucky enough to find one for sale US made PTR handguards can also be found in the correct HK33 length (unless you want use a US made rail system, which are more common but less "traditional" looking.. and they are HEAVY on an already heavy SBR). Using any of these alternate parts will prevent you from having to use the expensive RCM bolt head assembly... but if you want an A3 telestock you will have to use the RCM bolt head to keep the parts count up. Likewise if you want to use an Ambi lower... you will lose one US part (the trigger box) and have to replace it with another, usually the handguard if you can find one. You cannot use an RCM US made bolt carrier due to the receiver block. You can also go the magazine route and use Promag US made magazines, which give you 3 parts (mag body, follower and floorplate), but Promag magazines are a little hinkey. I own one 20 rounder as a test mule and while it has worked for me, it is made of kind of shitty plastic and I have doubts about its long term durability.

Hopefully this helps you out. If you have any other questions I can try to answer them. The Z43P once SBR'ed and 922r'ed is a pretty nice platform. A tad on the heavy side but it shoots very smoothly.

Nice rifle and great post, very informative!

Wow JsARCLIGHT, that was exactly what I was looking for. I did talk to Zenith about the 922r parts and they directed me to a company that could assist.  Thanks for giving me the map I was looking for. I'd love to hear from other owners as well especially since there isn't a lot of chatter about these.

Great looking rifle Js. I'm looking at a HK93 and will want to do a conversion to HK33.

That is a great looking rifle!

Thanks for the info; I'm waiting for the stamp to come back on my Z43P and trying to figure all this out.  Any idea where to get a US made handguard that looks like the one in the pic?

How exactly can you tell the difference between 922r compliant and non-compliant parts? Most of the parts you listed don't  have a country of origin listed on the them nor do the parts you are replacing. 922r seems like a bogeyman law.

When I did the 922r changes to my Scorpion SBR all the parts looked the same and with exception of the stock and mag end plate which did have U.S. Markings.

I have been looking for a stamped US made Tropical HK33/93 handguard ever since getting my Z43P and have yet to find one.

I've heard conflicting reports... Some people say that Bailey made his own when he was making SW93 clones 10+ years ago, as a lot of his SW93 guns had green furniture (which is very rare for 33/93 guns). I've also heard that PTR made them for their K3P / G3K clones, but when I talked to PTR they told me they only use German handguards on the new K3P guns. PTR has made handguards in the past, but they always seem to be sold out everywhere... my guess is they stopped making them. I have seen 33/93 handguards come up for sale on various forums claiming to be US made, but they never have pictures to corroborate any US markings.

So my best guess is that any US made 33/93 handguards that may be out there are in the secondary market and are probably old. And they also may not even be marked US made. Typically the folks who make the US MP5 furniture put "USA" in the date code block, and the date code block on 33/93 handguards is right behind the sling attach hook on the left side, clear as day. Also if someone could confirm I think the Malaysian contract handguards that come on the C93 rifles have blank date code blocks?

Long story short the US made 33/93 handguards are rumored to exist but I have never seen one. It is most likely the path of least trouble to just go with a German handguard and make up another part somewhere else like in the trigger housing. I assume you want additional US parts to either use an Ambi trigger pack or an A3 telestock. Your road to either (or both) of those unfortunately goes through ProMag town.

US Made Flash Hider
US Made Trigger
US Made Hammer
US Made Sear
US Made ProMag Magazines (3 parts, Body, Follower and Floorplate)

Its the only way to get enough parts to reach 7 but still have a German handguard, German trigger housing, German trigger box and German A3 stock all at the same time. You are avoiding the costly RCM bolt assembly but you are gaining the costly Ambi trigger assembly and ultra costly A3 stock... and you are also dooming yourself to ProMag magazines for compliance.

The parts are individually marked either with "USA" or with other identifying markings on them. For the parts I listed above:

- US made flash hider is simply engraved USA inside the lip, I'm not sure who made it I got it from RobertRTG as it was the only US flash hider with a retainer ring
- US made (PTR) buttstock body has a "scorpion" logo embossed in the flat area where the sling post is. The scorpion is PTR's logo, indicating the stock is a PTR USA part.
- US made trigger is engraved PTR91, indicating it was made by PTR USA.
- US made sear has a little black wing with a "B" logo engraved on it, indicating it is made by Blackwing USA.
- US made hammer also has a little black wing with a "B" logo engraved on it, indicating it is made by Blackwing USA. (there are also PTR made hammers marked PTR91)
- US made trigger box is engraved TPC USA really big on the side
- US made (RCM) bolt head assembly has "R.C.M." and a part number engraved on the side, indicating it was made by RCM USA.

Edit: German furniture always has a date code somewhere on it, using German alpha to numeric. Some brand new German furniture has the box but no date code. This makes figuring out if it is German or contract made (Turk, Malaysian, Paki, or ?) more difficult. US made furniture typically also uses this date code box, but they simply put USA there instead of a date code. Nearly all German trigger housings have engraving or markings on the front vertical metal surface that sits flush with the receiver at the magazine well. The newer ones even have the HK logo, a date code and a part number.

Suffice it to say US made parts are well aware they are being bought for 922r purposes and nearly every one I've seen is marked in some way to make it obviously an American part. The tricky stuff comes in with people passing off import parts as US made, specifically the parts that have empty date code boxes... but that tends to rarely happen as they'd be worth more as a legitimate German part if they are such, so what you typically have are people trying to pass off Turk, Paki and Malaysian stuff as German.



It is funny you mention the Scorpion. I have one as well and I've SBRed mine with the 922r stock kit. If you look closely you'll see that the parts NOT marked USA actually have tiny little differences in them that overtly identify them as US made parts. For example the US made flash hider has an extra ring engraved around the muzzle end, and if you look at both parts side by side you'll see it.

As for 922r being a bullshit law I am in complete agreement. But that doesn't mean I want to have the alphabet boys crawling up my anus over it... even though there are no actual cases floating around of them prosecuting a lone 922r charge. It is usually seen as a "tack on" charge... they get you for one thing then add it on to pad your charges. But that doesn't mean we should ignore it, as nobody wants to be a test case. Being a test case is usually very expensive and detrimental to one's legal heath. Hence why it is best to keep your receipts and a good "trail" of your parts replacement, so if god forbid you do ever find yourself standing tall before the man you have something you can give your lawyer to make the charge go away.

This is why I probably won't buy one.  
Non buffered carrier prevents you from running the cheap ATI MP5 A3 and Choate side folding stocks or the new folding SB brace.  
Can't install a aftermarket or surplus carrier with buffer because of the receiver block.
To do a A3 stock you would have to buy a real, really expensive, HK93 collapsible.   Don't want a A2 as I already have a Vector 93.

Yeah I forgot to mention the unbuffered carrier. Oversight on my part.

Which in and of itself is a weird thing because the gun comes from the factory with a metal MP5 endcap, the exact same part MKE puts on the 9mm guns that uses the rubber MP5 H buffer... which is usually not a good idea with 33/93 unbuffered carriers as they tend to beat the rubber H buffer to pieces.

I know somebody makes an AR stock adapter that fits the metal 33/93 stock bracket, which permits a mechanical buffer.

Two members on HKPro stated that MKE responded by saying the the pistol configuration will absorb some of the recoil, and the mechanical spring buffer will not be needed.
However, they do suggest using the proper mechanical buffer in the stock when it is in the rifle configuration.

Js,

Could you post a few more pics of this rifle? Looks great and I'm wanting to copy. Where did you buy the handguard? Thanks.

Handguard is a German HK part that was purchased through HKParts HERE

I haven't taken a ton of pictures of it and this is the only other one I have uploaded right now.

Man that is sweet. Thank you. I'm gonna go ahead and get one. Now I'm gonna have this, SP5K, and Z-5RS all pending on Form 1's. Probably be approved by Christmas 2017

ETA: have you weighed it loaded? 8-9Lbs?

With an empty metal HK 30 round magazine inserted and that rinky dink scope still attached to it my bathroom scale shows it at around 9 pounds (digital scale, fluctuating between 9 and 9.25).

This shitty Target scale is really only accurate in quarter pound amounts and my guess is that it is probably wildly off at the super low end. A full size HK33 weighs like 8.5 pounds or so, and this scope can't weigh all that much by itself.

You and me both

I thought I'd bump this thread instead of starting a new one.

I was thinking about getting a Z-43, but instead of registering it as an SBR, would pinning this flash hider make the barrel 16" overall?

https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=501&idcategory=164


I was thinking that it could be a fun little project to make a magwell adapter that would allow AR-15 mags to work in the Z-43.

Something to consider is that a real HK33K barrel is 0.6" longer than the Z43P barrel (12.7 vs 12.1, rounded up to the nearest tenth), and that those HK flash hiders reflex over the barrel at least a half inch if not more. I'd have to drag out my Z43P and measure the threads to see how much length is lost to the flash hider reflex. I do know that the flash hider butts right up against the front sight tower.

If there is more than a half inch of reflex on the flash hider it will be just a smidge below the 16" OAL requirement.

Edit: Someone in the reviews for that flash hider mentions this and confirms that it will be too short on the Z43P, but says that the longer G36 version would work.

Thanks for the reply.  This is the G36K flash hider:

https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=16281&idcategory=181

It's listed as 4.8" OAL (as opposed to the regular extended flash hider, which is listed as 4.37" long).  FWIW, according to the HK website, the G36K has a barrel length of 318mm (~12.5").