I emailed them Sunday and had a reply Monday. It's the canned response they posted in the other thread but they did offer a refund. I made mine fit (to be posted in the fitment thread) but with the issue I had making it fit, I would not do it again. Had I known what it would involve, I would have requested a replacement or refund. These are far too expensive to have to deal with this. There are far too many complaints on different boards concerning this latest batch.

Weird double tap. 20 minutes in limbo.

Odd.  No reply from you in spam.  My email went out on Sunday to your "sales" email.  No typo either, as it was a direct reply to my order (screenshot).



Anyway, neither here, nor there - just want to be able to return this stock for one that's in-spec or for a full refund.  I can post pics in comparison with my other stocks, end caps and rear of guns to show that this isn't merely a "tight" fit or due to paint.  The top of the end cap on the stock - the rolled circular part - doesn't line up properly with the receivers, and I'm not talking about on a sample of just one MP5 style gun from one manufacturer.

While some people might be able to force them on with a dead-blow hammer, I don't think that would be considered 'best practice' for putting on an HK style stock, as HK stocks are intended to be user serviceable without needing tools.

From the email posted above that was from Atlantic to another user:


I don't disagree with that, but that doesn't seem to be the case here.  Reports of it not fitting on MKE's, Zenith's, PTR's, HK's and potentially others I've missed.  I think that the tolerances may have skewed a bit too far in one direction on this batch.

While I don't have 25 years of experience with roller delayed HK guns, that's the first time I've ever heard that it's "normal" to need a dead blow hammer to install a stock on an HK gun.  I have or have had 11 different HK style roller lock guns over the years and have never needed any tools, much less a hammer of any sort, to put stocks on them or remove them.  That includes guns from several manufacturers as well as stocks from several manufacturers (MKE OEM, PTR, HK, AC Unity...).  When you're getting a LOT of reports like this from multiple people on multiple guns makers, you have to look at the commonality...  it's not the guns in this case - it's the stock with the issue.

What email address should I use to reach out?

Note that it is not my attempt to point fingers or bash.  Atlantic is a great company - I just think they got a bad batch of out-of-spec stocks from MKE.  If these stocks were $149, you wouldn't hear a peep from me, but for $379, they shouldn't have these issues.

I did reach out to [email protected] on Sunday.  See my screenshot in my post above yours of the email.


Here's my informal testing:



The guns I used are:

- MKE Z5-RS, imported by Zenith (purchased from Atlantic Firearms, in April 2014)
- MKE AP5, imported by Century (also purchased from Atlantic Firearms, in March 2022)
- HK MP5SD kit on LSC flat

The stocks and end caps used:

- MKE OEM metal end cap (never been shot with the cap on - came with the Z5-RS)
- MKE OEM metal end cap (never been shot with the cap on - came with the AP5)
- ATI A3F stock (purchased new from Atlantic Firearms some time in ~2014)
- POF A2 stock (purchased new from Atlantic Firearms in 2015)
- HK33 used stock (I have two, but only pictured one, as the fit was identical as tested - purchased as used surplus from Apex)
- Choate polymer end cap from HKParts or Robert RTG - don't recall.
- MKE A3 stock purchased new in January 2024 from Atlantic Firearms

The MKE AP5 is brand new, never been fired.  The MKE Z5-RS has had only about 500 rounds through it.  The MP5SD has had about 1K rounds through it.

I'll save everyone the suspense...  every single one of these stocks and end-caps, save the MKE A3 will fit easily on each of the firearms here with no tools, no banging it on the ground to seat it - but just using my hand to lightly fit it on.  None of the stocks have any wobble and they all fit very well with no play.  I even removed all the lowers and tried fitting all the stocks and caps on just the rear of the uppers (to remove the lower from the equation) with the same results.  Only the MKE A3 would not fit on any of the guns.  I *want* the MKE A3 stock to work, but I am not willing to use a dead-blow hammer to pound it onto the guns, nor should that be considered acceptable or normal, IMO.

I have video of me fitting all of these on the guns and you can see how easily and solidly they all fit in the video, save the MKE A3, which won't even align with the upper receiver.

PM sent.

I was going to push for a refund, because this sumbitch was TIGHT.  Like, ridiculously tight.  I’m used to AR milspec (read:sloppy) parts that just fit together.  This stock is not that.  It is TIGHT.  Did I mention how tight it is?

As my wife will tell you, I’m like a pit bull with stuff like this.  I just can’t let it go. After reading a few posts here where people said they had to sand off paint and drive the buttstock back and forth with a mallet to get it to loosen up, I figured what the hell.  

Let me tell ya now that I’ve done it, the paint on this thing is THICK. Yes, the end cap will probably scuff the paint on the ass end of your gun. It’s ok.  

Once I collapsed / extended the stock a few times I started to see where the wear spots are.  I hit them with some 200 grit sandpaper and continued to cycle it it.  It got easier and easier.  Then I pulled whole thing off, cleaned the rails, lubed em with some oil and put it all back together.  Now it slides fine and has zero play when locked.  Still could stand to loosen up some and I’m sure it will over time.  There are a few small areas where the paint is wearing all the way through. I’ll cold blue those and they’ll be fine.  


Point is, you gotta be your own gunsmith on this one.  It will fit, but it will take some fitting.

So here was my experience.  I was the same as everyone else, as soon as the notice came out I pulled my car over and ordered one.  This was my second attempt at trying to get one.  I had it shipped to my work where I knew someone would be able to sign for it at all times.  After some time I did not hear anything about my order so I decided to contact Atlantic.  They were questioning why I sent the stock to a different address than my billing address.  I had to explain why.  I guess they felt I was a fraud.  While waiting for the stock I began reading the issues people were having and  I was going to cancel my order yesterday.  I walk into work yesterday and the stock is waiting for me.  The finish was decent but I had to wait all day to see if it fit.  When I got home I carefully placed it on my PTR and tapped it with a rubber mallet softly.  It went right on!  It is snug and locks up tight.  Only some of the paint is coming off of the rails with repeated collapsing and extending.  I am happy I did not cancel my order!

Update on mine.  Atlantic sent me a replacement stock and this one actually fits.  No hammer or other tools needed.  It's a tad bit more snug than my other stocks in both putting it on the gun and retracting/collapsing the stock - but it fits and can be removed without the use of any tools (or the floor) - just using my hands.

Clearly, some of the batch they got were out of spec and I was one of the unlucky few who got a bad one initially.  But clearly, some of them are just fine, and that's why we buy from a company like Atlantic that will stand behind the product and make it right!

A+ for Atlantic Firearms for their service and communication!

That is awesome news.  I also had one of the out of spec stocks and sent it back.  I received the shipping notice today for the replacement.   Hoping I have the same experience.

Finally got around to trying it out on a MKE Z5RS and it was perfect fit... took a mild palm strike and slight push for it to go on, but is appropriately tight and smooth in overall operation.

Sorry to hear that some had issues, but Atlantic Firearms is an excellent dealer and I am sure that any issues will be resolved.

Mine fits great. It just shaves off a pile of paint every time I open or close it. Oh well. I have an original 2-pos HK A3F stock too…I just wanted the original look.

Good job @ATLANTIC-FIREARMS taking care of your customers.

For those who are experiencing tight fitment, I'd try and source a friend with an SP5 and see if it will fit their receiver (don't force it on and scratch up your buddy's gun!).

If not, I'd get a replacement.

Clones are notorious for 1) being out of spec 2) having "extra" paint. If the stock fits the SP5 fine, it's probably your clone and then, light sanding of your clone receiver (or other more drastic measures) might be appropriate.

Mine fits my SP5 just fine. But it scrapes the paint off the stock rails every time you open or close it.

It eventually stops doing that. Eventually.

I’m very happy to report that the first stock that I received was definitely out of spec.  My replacement came today and it fits perfect.  Slips right over the end of the receiver and with slight hand pressure pins into place.  I’m very happy with it.  

So now I have a German gun with a Turkish stock and a Turkish gun with a German stock .

I've had similar but acceptable issues with my new A3 stock... tight but workable.

My question for those with more experience with these is about the closed position. The arms of my stock when closed, seem splayed out slightly and not snug against the receiver. I can squeeze the end of the arms like a big pair of tweezers. It's not real bad, but I wondered if it is normal

The model for the C93 fits and operates perfectly with no wobble. The plastic butt is green.

I bought one for my PTR91 back around Thanksgiving. No fitment issues.

The MKE A3 stock was very tight going on at first.

Some paint got shaved off in a few places.

It fits and functions great.

I bought a Pakistani A3 stock years ago when it was the only A3 stock available under the crazy high prices at the time.

The MKE stock is so much better than the Pakistani stock, I apologize to anyone here who has experienced the trauma of buying/using a Pakistani A3 stock and reminding them of their awful misfortune.