Zenith offers the original design:

https://zenithfirearms.com/product/2-position-a3-retractable-stock-mke/

Regardless of which A3 stock you pick up, if you want it updated to the multi-position F model, give the Zenith Custom Shop a call:

https://zenithfirearms.com/videos/?vimeography_gallery=5&vimeography_video=277345458

 

I also noticed that the “A3” stock designator actually leads to a wide variety of stock possibilities. I was looking for a tail hook version as a work around to the NFA route, but apparently you have to permenantly modify an A3 to go that route; and I just am t comfortable enough for that route myself yet...

 

Here you go. Left to right:

A3 (first generation) "Convex"
A3 (second generation)
A3 (later second generation)
A3 (third generation) "F Style" aka: "Universal stock"

See next page of this thread for an example of a 3rd Gen stock with no MP5-10/40 bolt hold open cutout (thank you @MG34_Dan )​

(not pictured) A3 (third generation) "F Style" MP5-10/MP5-40 long arm "Universal Stock" - See @MG34_Dan post on the next page

Note that the A3 (first generation) Convex was only intended for the 223/5.56 caliber rifles** as its "arms" are too long to fully collapse when mounted on an MP5

 

Here you go. Left to right:

A3 (first generation) "Convex"
A3 (second generation)
A3 (later second generation)
A3 (third generation) "F Style" aka: "Universal stock"

Note that the A3 Convex was only intended for the 223/5.56 caliber rifles as its "arms" are too long to fully collapse when mounted on an MP5

Thanks for this Maim.

How much of this applies to the G3/91 A3s? Can you post similar pics and info for those? It would be appreciated.

 

Outstanding.

 

I would go with a factory A3 F from Numrich. I have never found one any cheaper. The F is superior in my opinion (unless you are going for a "look"). Also, why go with a knock-off "universal" F that has a fork cut out for a 40/10 BHO if you have no intentions of ever needing it. Just my opinion and I'm sure there are various others.
https://www.gunpartscorp.com/products/1573180

 

I would go with a factory A3 F from Numrich. I have never found one any cheaper. The F is superior in my opinion (unless you are going for a "look"). Also, why go with a knock-off "universal" F that has a fork cut out for a 40/10 BHO if you have no intentions of ever needing it. Just my opinion and I'm sure there are various others.

I totally agree with this. The BHO cutout is annoying and considering how few 10mm/40S&W MP5s sold, there are a remarkable amount of stocks cut for them out there. (though the one pictured in my picture (displaying the four stocks) is an OEM HK MP5EA3 Universal Stock)

 

Yeah…..you say that until you get hooked on the MP5 10mm......and start building the sh$t out of them. Go with it...that way WHEN {not if} you get an MP5 10mm, you can move it from all 15 of your MP5's...… :biggrin:

 

When did the F come into production?

 

That's a great price! I was getting ready to pull the trigger on one from brownells for 468 then ran across this post. Hard to believe it's HK for that price but seems like everyone here is in agreement that it is. Guess I'll have to order one

 

When I see an F stock with a .40 cut on it, I assume it's an ATI repro until I can find a date stamp. I had a bad ATI stock experience, so I am tainted now. The vast majority of F stocks with .40 cuts that you see are ATI stocks.

 

Sadly, no more date codes on HK furniture for several years now. None of the "F" stocks that I have ever seen have date codes (that's not saying that I have seen them all!).

Here's a few threads going back as far as 2010.

no-date-code-stock-normal
mp5-a3-stock-date-code-help
no-datecodes-recently-purchased-hk-stocks-handguard-normal
no-codes-now
mp5-a3-f-style-stock-question
a3-stock-identification-german-clone-longbuffer

 

Sadly, no more date codes on HK furniture for several years now. None of the "F" stocks that I have ever seen have date codes

I believe that is the general consensus. Fortunately, the ones I ordered from Numrich over the last few years did come in factory sealed bags with barcode.

 

This was very helpful as I have been so confused on which A3 stock. Thanks

 

There have been a variety of changes to the MP5 A3 stocks over the years. To the best of my knowledge, none of them had a convex shape to the butt plate. Even the prototype MP 64 had a concave shape.

One of the earlier A3 stocks had an all metal receiver end cap. Then, HK switched to a metal end cap where the rear portion of the end cap was plastic. HK also came out with a "universal" buttstock that had slightly longer forks and the bolt hold open cutout. This was intended to be used on both the .223 guns as well as the MP5 series. On an MP5, the longer forks would not let the stock fully retract. HK produced both the earlier A3 and subsequent "F" stocks with, and without a bolt hold open cutout. Then there is the multi position F stocks. Actually never had one of those, I have too many A3s as it is. There may be more versions, but that's all that come to mind.

 

outstanding info

 

On the universal stock, how would they work with the .223 if it has an H buffer? Buffered carrier or do you change out the H buffer?

Also, this seems like a good deal considering recent prices. Not mine and no affiliation. Description clarifies it is not air soft and seems to have purchased from HKParts.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/293488177755

 

@willgaga

The non-pistol caliber stock requires a different buffer. It is an internal spring with a button plunger. The H buffer is not sufficient enough and if the A3 stock does not have the fore mentioned, then the BCG needs to. If you fire your gun without one of these buffers, it may/will damage the receiver.

 

Ok. Thanks, is is possible to retrofit a universal stock with the correct stock buffer for the .223 or would you need to use the buffered carrier? I don’t think I have ever seen the buffer for the .223 for sale as a separate part, but maybe I have not searched correctly.

 

Buffered carriers used to come up all the time in demilled HK33s. Just keep searching and keep an eye out for it.

 

While we're on the subject of funky A3 stocks, how about this one? It appears to be an early HK A3 for and MP5 40/10 w/bho, but check out the length of the stock forks. They are very long and have three lock positions.

So far so good. Nothing really special. Now check this out.

Did you notice the third lock position?

Damn, those forks sure are long.

How much longer are they?

 

That's an A3 40/10 universal.

 

This may be a dumb question but Im trying to learn more and I want to eventually sbr my clone..

Does Hk still make the A3? I know everywhere is sold out now from I guess general clones and the big new sp5.

Will places eventually get a shipment and be back in stock or am I pretty much looking for used one now?

 

Yes the A3-F is current production. If you go back a few pages to my pic in post #4, it's the one on the right.

https://www.hkpro.com/forum/hk-nfa-talk/477978-mp5-a3-stocks-buyers-guide.html#post3435480

 

I have both A3 and F type. The Ftype had a longer length of pull, thicker pad, and multiple positions. The A3 is lower profile. There's some other differences but a lot of is it aesthetics for people.

 

On the universal stock, how would they work with the .223 if it has an H buffer? Buffered carrier or do you change out the H buffer?

 

As far as know, neither. Never tried using the universal with a .223, and not sure I would want to experiment. I’ve never read anything from HK about changing out carriers (that would make little sense) or altering the stock when switching guns.