Push pin lowers don't have a shelf preventing an auto sear, instead they have a blocking piece on the rear stock pin preventing an auto bolt carrier from being inserted.the carrier that comes with the gun will have the auto trip milled off. I like the pin lower, the frame doesn't fall off when I take the stock off.

"Back in the day" every semi-auto HK had to have the shelf, which is a semi-auto restrictive/blocking shelf.
Let me backtrack...
The first ever HK semi-autos imported here had pushpins, like the HK41 (and anything HK4x). I don't know how many were brought in; Wiki says 400 or less. They are super-scarce.
ATF almost immediately declared the pushpin to be no good, because the receiver is "too similar" to a select-fire receiver. "There HAS to be 'mo difference!," they said, so the modern shelf was born. This became the HK91 (and HK9x), and all subsequent clones' pattern until a few years ago. It physically prevents one from attaching a factory select-fire anything. (So did the earlier one, basically). Even if you use the factory-supplied trigger housing from the 91, which your select-fire pack could drop into, it now cannot attach to the receiver because the front-bottom corner is in the way when it hits the shelf.
It's not May 1986 yet, however, so then machineguns happen...
There were different ways they were converted, but in brief, third-party sears [most commonly] were used. They pivot in a location (pin hole) that is aft of where the factory sear/catch would be located, thus circumventing the physical restriction.
There's also the (much simpler) way of just chopping off the corner of a factory select-fire fire control box (aka trigger pack or just pack). This was not commonly done, due to limited availability at the time.
There's also having a "clipped-and-pinned" housing which will fit on the shelf, and is original select-fire dimension on the outside. These were the rage because they look legit. The packs were still semi-auto (unless you have a registered MG to go in there), and the blocking shelf was still in place. Zero receiver modification.
You could even do a paddle mag release (with ATF-approved modification to the receiver. ~No permanent hole all the way through.) This was, for a long time, the height of HK clone awesome.
The cool kids could even swap their registered MG pack/sear conversions into and out of these independently-semi-auto "hosts" whenever they wished, and they always looked the same (like factory HK military models) on the outside.
The MKE clones a few years ago were the first time (I think) that ATF ever allowed a variance to the shelf idea. There was still a restrictive rear protrusion/shelf, but the sides were narrow like original HK dimensions (so no need to clip/pin a select-fire housing in order to attach one; it just had to have an opening in the unseen frontal area to clear the restrictor shelf.) The restrictor would still block an unmodified select-fire pack from fitting in said housing(s). They even had paddle mag releases from the factory pivoting on (at first the ACTUAL same bushing as select-fire guns use WITH dummy pin glued in, and later a larger-diameter solid pin welded in place on one side). So this was cool. As a trade-off, the MKE guns were required by ATF to have a blocking piece welded into the bolt carrier channel in the receiver, which prevents a select-fire carrier from being installed. (The "trip" hits the blocker and stops it from being inserted).
With the earlier MKE ones, sometimes the glued pins would fall out. Then your slightly modded housing could actually be pinned with a real pin. Most were afraid to ask ATF if that was OK. (Letter writing is dangerous FYI).
So then POF gets approval to import the POF-5 with an actual pushpin already in the housing/receiver. I believe they too have the restrictive protrusion going into the housing like the MKE. They definitely have a similar/identical bolt carrier block.
Now the new/current importer of MKE (Zenith) got the same approval.
So cool! Now we can buy clone guns with with push pins!
This has led to more questions, such as:
"If it's legal to import them this way, can't I build one the same way in my garage?"
"What do I have to do to legally install my <insert MG conversion device> into it?"
The answers I've been browsing seem to say that if you mod your MKE/POF into the "old-school" semi-auto config, where it has NO push-pin hole of any kind, a big wide shelf, and NO bolt carrier block (after the shelf is swapped of course) then it's now legally/physically the same as any other legacy semi-autos out there.
I don't know the answers to other questions.
It would seem that what is legal to import what be legal to manufacture domestically, you know "equal protection under the law" and all that, but the ATF is not known for making sense, and I have not been following the situation that closely, hence my question on page 2 of this thread.



The spring-loaded carrier trip, to circumvent the block inside the receiver channel, is an idea that popped-up (pun intended) in the last couple years, from some clever members of the hkpro forums.
That's basically my recap. I may be mistaken about the factory HK91 housing (only / by itself) being able to accept a factory select-fire pack, but any clipped/pinned housing definitely can, and they are both considered legally unrestricted as far as that goes. If it (the entire firearm) IS full auto, there's (at least) one piece somewhere that is considered to be a MG. All the physical and historical variations can make things somewhat confusing. Then you get into the "wrong ways" people made/registered MG's. That's almost a whole other story. lol
Makes for interesting reading.
Linkies:
http://www.hkpro.com/index.php?option=com_content&view=article&id=141%3Athe-complete-reference-on-the-legal-nfa-conversion-of-hk-firearms&catid=4%3Aspecial-topics&Itemid=5&limitstart=2
http://www.hkpro.com/index.php?option=com_content&view=article&id=141%3Athe-complete-reference-on-the-legal-nfa-conversion-of-hk-firearms&catid=4%3Aspecial-topics&Itemid=5&showall=1
http://www.hk94.com/hk/topic/6337-heckler-and-koch-sear-faq/
 
 
 
 
 
 
 


 

Thanks for the video. It really helped clarify the magazine issue on the rifles. The fact the 10 round magazines are compatible with a de-banned magazine well bodes well and tells me the pin is very easily removed with minimal hand tools. Hopefully the muzzle break will also be easily removed.

I definitely will not be buying one of the first run Z-41's until I see how well MKE did installing the ban mag well pin and muzzle break. The ATI AT-43 had a blocked magazine well, but it wasn't clean at all.

Don't think HK roller lock style guns are the same as ARs. They operate completely differently. Ever see inside an HK trigger pack? Way more complicated than an AR...because it's zee Germans.

We inspected the magazine pin block on the new imports and it is very small, about half the circumference of a pencil eraser. Once All 922r parts are installed, it can be easily removed.
Zenith firearms also stated that they are planning on making domestically produced 922r replacement parts.

You will be able to order rifles directly from Zenith 922R compliant through their 922R Shop.

Do we know what the twist rate is on the Z41 and Z43?  I assume the Z41 is 1/12 but I'm hoping it's 1/7.

The ATI imports were 1/9 so I bet these probably will be as well.

Let's hope they did their homework and bring us a 1/7.

Hey guys.  Let me see what else I can fill in.  Most of everything I read was accurate or corrected by guys.  And thanks for posting the videos and explanations.  

The pistols are all approved and are being manufactured now.  The import date is set to be by April 15.  We have been taking orders for over a week now and will be filling orders "first paid, first served."  We have a couple of intro videos being planned that will give independent reviews around the time of release.  Be on the look out for them!  

The rifles ran into a snag with the ATF and the mod is designed and new prototype being built and will be sent to ATF shortly.  I think we corrected their concerns and it will pass and then go into production, hopefully with importation coming with our second import, set to be by July 15.  A word about the ATF, they do not tell you what to do at all, they just point to what the result has to be.  We (for better or for worse) designed our mods with the end result in mind.  

Some of the mods and the reasoning: military profile barrels so you can use any hand guard, original 15X1 RHM threading on rifle barrels with pinned, redesigned "muzzle brake," Navy style barrel end for 9X19's (3 lugs and 1/2X28 threaded end), 16.15 inch rifle length barrel so they are shorter OA, removal of the "shelf" in lieu of two takedown pins, welded block for FA sear pack (required), pin in mag well for limited capacity magazine (required), adding three mags per gun, adding Picatinny optics rail, extending warranty to five years, adding two extra takedown pins, a cleaning kit and a sling--all factory OME.  

To be continued...

Continued...

Some further specs on the guns: all barrels are cold, hammer forged, 32 Chrome molybdenum vanadium, all guns are fully manganese phosphate coated on individual external parts, and all have fluted chambers.  They all have 6 lands and grooves except the 7.62 which is 4.  The twist rate is 1:9 for the 9's, 1:7 for the 5.56 and 1:12 for the 7.62.  

Zenith Firearms has 3 tiered pricing for FFL holders with discounts based on a the amount purchased.  The prices have been adjusted to get rid of the "99" pricing because we don't want to dilly over a dollar trying to trick anyone.  They are what the website says, check out http://zenithfirearms.com.  And like the Facebook page too.  We do most posting on those two sites with FB being updated the most.  

Zenith is in business to sell the highest quality firearms, parts and accessories and believes that our customer is who we serve, to that end we want a partner-like relationship.  Please feel free to write to us at anytime.  

Thanks!

I will order as soon as it becomes available.

Any word on whether the pistol variant of these guns can be legally made to function with a registered HK sear? That's what I really want to know!

Very good.

I'll take the mp5k clone please

Atlantic Firearms, thank you for the reply. I've heard that people have made modifications to guns with similar anti FA mods but haven't heard anybody give more information as to what they did and how they know that its OK with ATF. Hopefully someone will enlighten me! I'd really like to be able to use an MKE with a registered sear.

While I can't peak to the configuration of ZQ imports I can address the mods for the older ATI guns.
Here goes........................

Step 1 Buy a wrap around style shelf, you know the classic HK semi shelf.
Step 2 Take your hacksaw and cut the MKE tongue type shelf off of the back of the magwell.
Step 3 Weld on your new shelf.
Step 4 Grab the Dremel and go all WECSOG on the FA carrier block.
Step 5 Install your FA BCG.
Step 6 Grab your favorite clipped & pinned FA (multi) position trigger housing and insert your trigger pack into it and mount to your gun.
Step 7 Install the stock of your choice.
Step 8 Lock and load, its fun time bitches.

Atlantic, can you give a timeframe for when you will be getting these ? I'd want to purchase from you.

Are there any differences between the new MKE and the original MKE imported several years ago?

bump

Any updates ? April is almost here !!!