Perhaps - But a CZ Scorpion will.  Right out of the box.  No special ammo, or parts needed.

HKs are temperamental design - work when everything is perfect as German Engineered = 7 parts where only two are needed.

I have many and built a few - I love them but they are indeed something that like a piano needs proper tuning to run perfect.

I'm sure MKE and POF turn out good guns - they wouldn't sell them for decades to military groups without it being good enough.  They can all be fixed its just a matter of do you want to be an HK smith "piano tuner" or a shooter?

What does your ejection path look like?

For my mkes, they were all over the place.
At first no issues using hk and mke mags.

Later i started getting a random fte.
I also noticed exp on the full size, brass was hitting the top of the ejection port.

I fired the parts cannon at ths problem, hk ejector, spring, new extractor plus new copper colored spring.

Use a L shaped pick to spin the extractor spring into place.

The old extractor spring was weak, it nearly fell out.

Afterwards everything changed, extraction was consistent, it stopped hitting the top of the ejection port, and i haven't had issues with either since then.

I'll set up my phone camera on a tripod and see what happens with the Winchester 124gr Nato Spec 1200fps MV Ammo & 4 Zenith marked KCI Mags.

I plan to also shoot my MKE AP5 at the same time with a mixture of ammo - CCI Blazer Brass 115gr 1145fps MV & CCI Blazer Brass 124gr 1090fps MV using 7 MKE mags.

Have someone help you and shoot it in slow motion zoomed in on the chamber

I would also consider for anyone having issues to get a new factory Recoil spring/rod assembly.

I've found a few when swapped out would run better when replaced.  Almost felt as if the factory springs were a tad bit heavy on the MKE clones.

3 videos. I got 1 mag to run all 25rds of 124gr Nato Spec FMJ.



Part 2 - shooting the Zenith Suppressed.



Part 3 - the 500rd break in continues - more jams. Actually I'm getting near 1k rds fired.
Also Pogo-Stick method of clearing jams.

That sucked to watch (the jamming - not the videos).  Hope your next purchase works out better.

If you do decide to install the HK parts, you gotta do another video.

Will do. I also want to try out those HK mags.

Would be cool to see how they feed other ammo to. Like some Remington 147gr and maybe even some hollow points.  We'll the AP5 any way.

However I do think Changing the extractor spring may help on the zenith Failure to Eject.

It is possible that last round issue maybe Exaggerated by your forearm pressing back angling the magazines into a nose down feed?

The AP5 is a keeper and I will run some other weights of ammo through it suppressed and unsuppressed.

Anything is possible, there's not much to hold on to as far as the fore end goes.
A good way to test that forearm issue would be loading a couple mags with 4rds - applying pressure to the mag vs no pressure / no grip on the Fore end.

I shot my HK SP5K-PDW today. 300 rounds of 124gr Speer Lawman TMJ with my 10 HK factory magazines. As always, 100% flawless operation. I have both the PDW and full size SP-5 and both have never had a malfunction of any type. Just boring 100% reliability resulting in my focusing on shooting enjoyment instead of fucking with a POS firearm like you are dealing with.

Are you shooting the SP5K-PDW suppressed and did you have to mess with rollers and 80 degree locking pieces?

I wonder if I should just get the SP5K-PDW and not mess with suppressing it?

I do have a suppressor and when I use it on the PDW, I do install my HK 80 degree locking piece (which has optimal bolt gap with the stock rollers).
The amount of money you've wasted on that POS Zenith, in ammo alone, would have paid the difference for a real HK.

I'm not quite up to a $1000 blown in ammo yet and shooting is fun no matter what. Good way to practice those failure drills...

I was just thinking I may try swapping bolts between my AP5 and the Zenith. That might eliminate some of the guessing game. Yes I should just dump the damn thing and get an H&K.

I'm glad I bought the MKE AP5 and that it works flawlessly, so far. If I only had the POS Zenith, it's very unlikely I'd buy another HK roller delayed roller lock firearm ever again. I played with those junker HK91, Cetme, and FAL clones back the day. I didn't find those reliable either. Not enough to make me wish for a real HK 91 or a true FN FAL.  

I'm really not a delayed roller lock enthusiast. Give me a piston operated AK or M1A. They go bang. No playing with rollers or adjustable gas systems (aka FAL).

I've watched your videos and you're right, an AK is more you style.

LOL

After watching two of your videos, I was curious how many times have you replaced the extractor spring?  Once you get jams and double feeds, the extractor spring begins to lose tension. Some people will slightly bend the spring as a temporary fix. It will work for a little bit but will fail.

Your gun has a few areas to address before declaring it a jam-o-matic. In a perfect world, a newly built gun should run like a Swiss watch and in a perfect world, I'd expect that out of an HK because they have all of the machinery, tools, technology, and staff to properly assemble a gun that's been in their production for over 60+ years. No matter what brand you buy, you should aim to buy German mags. When you have a mixture of mags and ammo, you introduce more variables instead of isolating what is causing the intermittent/frequent failures.

Three things that you can do is to make sure the gun is clean and lubricated. Use good ammunition, and use a reliable magazine. You went through a lot of ammo but I don't see a German HK mag in your two videos. A 500 round break in period is suggested since newly built guns may need time for parts to mesh/cycle and sometimes it allows moving metal to smooth out in areas that a newly formed/bent/assembled/welded, etc. This period also gives new springs time to cycle back and forth. Some would argue that 500 cycles will do nothing to the spring tension. You can also leave the action open and hand cycle the gun to smooth it out. If you feel any binding along the bolt carrier travel, that could cause the "timing" of the BCG to be off.

You gun works, but not reliably. This tells me the timing is off, whether that is because the extractor is not gripping the expended casing and causing a failure to extract, eject, and feed.  Change the extractor spring.

You have mags that you suspect have spring failure because there are a few rounds left when your guns jams. Try loading 3-4 rounds instead of 25 and fire them slowly to see if the magazine tension is sufficient. You can eliminate magazine concerns with a factory German mag.

Your gun came with a 100 degree locking piece in the bolt carrier group, but did it come from Zenith with the pistol brace or was this something you added? Are you still using the 100 degree locking piece or did you switch it to the 80? An 80 is recommended if you are running 147 grain suppressed and a stock. If you have a sear and running auto, an 80 degree LP helps the gun cycle reliably (slowing down the BCG) without beating up the receiver and causing the BCG to move faster than the magazine follower is able to get the rounds up to the feed lips before the BCG goes into battery. If you're running an 80 degree LP and the recoil rod spring is too stiff, the bolt carrier group can also not cycle back far enough for the BCG to fully eject, hence the double feed.

You have several things to address before your gun is considered a jam-o-matic. You could also swap parts from your MKE and see if the bolt head is the issue. Since your MKE is reliable, a bolt head swap as well as the locking piece will tell you if it's a bolt/LP issue. I could have diagnosed your gun faster and fixed it than me typing this reply. I highly doubt the barrel or trunion is the issue..

 The CZ is a cool little blaster.  The problem like most blowback designs is the muzzle is like a bucking mule.  The recovery time for each follow up shot is a huge difference.    A 9mm sub gun is already underpowered so fast follow ups are must for self defense.

As stated before it is a really simple machine, if the bolt gap is correct (in range) the Extractor itself, the tooth or fangs may not be sharp, the spring may not have good tension, finally the ejector, the EXTRACTOR has to hold the case until it hits the ejector, if the ejector geometry is correct it is capable of knocking the case out the side, so Extractor and Spring are the main culprits. switching to the MAD or E bolt is changing the extractor to a completely different design, using a coil spring instead of a torsion style or leaf style, i.e. better and longer lasting. the Extractor doesn't rotate in the same way it is straight in and straight out, not a pivot or angle. not that the original is BAD but there is a newer more reliable design. I have a fresh RCM bolt on hand that I can swap if I want, have not done it yet. but I can if I desire. I do not have a MAD or E Bolt. but I am betting I can put a new extractor in and a new spring and it will work fine. My ZF5-p now works 100% reliably.

Thanks for the feedback and I will definitely take your recommendations. I would rather get the gun running than spend another $1000 on a H&K.

I'm still waiting for my HK Parts order to arrive which includes 2 H&K extractor springs, H&K extractor, H&K ejector, 2 H&K 30rd mags, and a RCM 80 degree locking piece.
I agree, I should try swapping in the MKE bolt / locking piece and see if that changes anything.

I didn't know that about extractor springs! FTE / FTF = change the extractor spring.

Just for the record the Extractor Spring is a Consumable item, it dies in use.
the Extractor to lesser extent, when a case gets hung up and holds the extractor away from the bolt the spring will likely bend, German, HKP, Zenith etc. Most of the parts are functionally identical anyway.
Spring material and rate. the extractor "MAY" be a problem, I too have a spare extractor en route as well as some more Extractor springs the Black "Rifle" extractor springs which are also recommended if the new Copper spring doesn't help. the MAD or E Bolt is to fix an issue that exists with aging Mp5s as well not just semi autos, or clones. totally different geometry/design on the extractor. and the entire bolt.

A lot of this stuff is in the Hk Armorers manual as well. under Trouble shooting.

given that when ejection does occur it is energetic I doubt there is an ejector issue, but the later style ejector geometry may help.
Extractor SPRING is the most likely followed by the Extractor itself. since you have a working AP5 and a non working Zenith swap the lower on to trouble shoot the ejector.
swap in the bolt head (check the gap) to troubleshoot the extractor/spring.

I have never tried anything but hk and mke mags, i have mostly all hk mags.
I have observed minor issues with some of the mke mags i picked up, but not with function.
Issues like a sticky spot when loading, but they function 100% for me.

The locking piece the mkes comes with works flawlessly with 115gr CCI blazer and the loose packed cci independence stuff.
I think that's a 110 or 100 degree piece?

My K runs 124gr blazer brass smooth as silk with the 80-degree locking piece.

Just watching the first video, that p ejection path is all over the place.
Are you seeing any paint chipping or brass marks being made at the top of the ejection port?
Check the brass for signs of impacting, like dents.

I bet the ptr paint job is better, but my mkes would chip the paint a bit showing me something weird was happening.

After firing the parts cannon with hk parts, my ejection path is consistent, not too high, not too low.
And my brass all piles in the same spot (unless I'm moving around).


I suspect the things that really helped me was the hk ejector, sping, and replacing the extractor spring with a hk copper colored one.

Watch some youtube videos on how to do that as to not tweak it.
I use a cheap amazon special pick to spin it into place with a little oil to prevent binding.


For me, i figured as long as i was paying for shipping, i ordered an extractor, ejector, springs, etc. For both of mine.

Nothing more frustrating than doing constant clearing... lol

"Spinning" it into place is not the HK factory approved method of replacing the extractor spring.

Twisting then... lol

Whatever you want to call it, you're doing it wrong.

The other method forcing the spring straight in there can remove tension from the spring.
The twisting method doesn't, you just want to avoid letting the legs bind up.

The bad part with it, you really need a pick to grab the end of the spring.

I got a deal on 4 hk mags from euro optic, I was pretty excited to get them as I was using lowly kci g2 and mke mags.  Those 2 brands fit snug into 2 ptr and an ap5.  The hk mags arrived and sure were pretty, but they were alot looser in all 3 mp5.  I mean fore and aft movement with a couple also exhibiting sideways slop.  They fed fine, the important part, but I'm lead to believe a wobble free mag fitment is also important.  I've yet to have any issue with kci or mke mags with my 124 nato spec reloads(1170) or 147 sub reloads(975fps).

I cleaned it and replaced the extractor spring and extractor. Testing the old extractor and spring, it would hold a loaded cartridge but shaking it would cause the cartridge to drop out. With the new extractor and spring a cartridge snaps under the extractor and doesn't fall out when shaken.

Did I need a new extractor? Uncertain while there was no damage to the edge, I did noticed a little raised mold mark under the Zenith extractor claw that isn't there on the H&K claw.  

Checking the bolt gap: .020 fits .021 doesn't.

I did not install the RCM 80 degree locking piece.

I just shot 50rds of 124gr Winchester Nato through it using the 2 H&K mags and... it works!!!

Helpful videos:





I guess it's true, any FTF, FTE, Double feed = change your extractor spring.
Use the shitty KCI / Zenith mag that comes with the gun and results in a last round FTF/FTE, now you get to change your extractor spring.

Tell me you don't know the century/mke relationship without saying you don't know.  Century sucked at building pretty much any pattern rifle, but century is just the importer of the mke, same as zenith.  They were/are qc'd at mke before leaving turkey, irregardless of importer(zenith or century).

Spoke too soon, tried a MKE mag - same failures. Went back to the H&K mags - same failures.

Is this a new production zenith, or an old zenith imported mke?

The official HK way, as taught to us at HK factory armorer school, is push it straight ahead against an armorer puck or similar. But you do you. I'll do the HK way.

Then your clone magwell is out of spec.

So not a mag issue, atleast not entirely mag issue.

All 3 clones, bought over 3yr span......and kci and mke mags fit real well.....and ac-unity mags would not even begin to go in all the clone magwells......sounds like the hk mags were a smidge undersized.  Didn't you say mke is all on hk tooling and made by hk instructed guys?

HK says that tooling is decades old and HK no longer provides any support for clone manufacturers.

Yeah, but the clone owners cling on to that tidbit that their clone was made on HK tooling by HK trained workers, when in reality, the tooling is decades old and HK doesn't provide any support, to justify in their minds that their clone is "just as good as"...

Never mind. Not going to fall into a GD argument.

One can also say that that same line of thinking is used by hk fan bois to justify the 3x price....just sayin.

Sorry, not sorry.  My shit box "clones" run fine on multiple mags, they don't need uber hk mags to function....but they're shitbox clones, so.....

New production made in the USA Zenith.

Some of us can easily afford the price of a real HK... just sayin

Id rather make friends with people that can only afford clones instead of a douchebag like you.

This is exactly why I deleted my GDish post.

Mine seems to run just fine…

Attached File

I wonder why?

Love the classic 3 pt. sling too.

Does the backplate of your brace have a hole for your recoil rod to nest/sit in?

I've noticed some aftermarket braces and back plates do not - this can allow the recoil rod to move slightly.

The recoil rod should nest inside the hole/recess so it doesn't move around - it should be strait and not wobble around freely.

Give it a look.