[dzmedia]

Hey guys,
Newbie here and i've searched and searched and can't find any recent info on where i can get an adapter to mount an mp5 a3 retractable stock to my mpk clone
I know there were a few guys that made them but i havent seen any recent threads or way to contact them.

Any help would be greatly appreciated. Thank you for your time and this awesome wealth of knowledge.

 

[kbinmt]

As far as i know, Can't be a3 as the K receiver has welded reinforcements that block the channels.

 

[dzmedia]

You are Correct, Kbinmt. Those will be ground off and the receiver refinished. The adapters i have seen that were previously available extended into the receiver to help reinforce it.

 

[ecsuser]

S&H Arms used to make an A3 stock adapter - only seen pictures though. I see that Fleming has an MP5k stock adapter that might work if you modify it to facilitate the rails. You may want to email Robert to see if they are ever expected in stock again.

MP5K to MP5 Stock Adapter, SP89, HK94, HK, Fleming, HKK-1258, RTG Parts

 

[dzmedia]

Called them and also put myself of the waiting list. It would be great to get one but didn't flemming have some legal issues with the ATF and being prosecuted for something in the last couple years? With like a 14 year prison term?

 

[jsurowitz]

S&H Arms used to make an A3 stock adapter - only seen pictures though. I see that Fleming has an MP5k stock adapter that might work if you modify it to facilitate the rails. You may want to email Robert to see if they are ever expected in stock again.

MP5K to MP5 Stock Adapter, SP89, HK94, HK, Fleming, HKK-1258, RTG Parts

View attachment 76610

Notice that the rear receiver reinforcement tabs have been removed.

 

[dzmedia]

Notice that the rear receiver reinforcement tabs have been removed.

Yep, Already plan on removing those.

 

[dzmedia]

So i stumbled on MFIAP.com they didn't have any adapters on their site but i still sent them an email. Within a few minutes i got a reply from Michael he didn't have any new ones but he had an 18 year old BCD manufactured one as shown in pic. He was gracious enough to let me buy it off of him. Once i get it and can get it fitted and installed ill post some photos.

 

[flybynt]

You will eventually regret removing those tabs in the long run especially if you use hot ammo or a higher degree LP...they are there to keep the receiver from deforming/spread out in conjunction with the 2nd stock pin due to the shorter stroke of the K gun / spring rate. They work much as the std mp5 end cap does on a full size gun to cover and contain the rear in spec with the 2nd stock pin.

 

[dzmedia]

You will eventually regret removing those tabs in the long run especially if you use hot ammo or a higher degree LP...they are there to keep the receiver from deforming/spread out in conjunction with the 2nd stock pin due to the shorter stroke of the K gun / spring rate. They work much as the std mp5 end cap does on a full size gun to cover and contain the rear in spec with the 2nd stock pin.

So you think instead of removing i should maybe remove and replace with ones that allow the slides to pass through yet still keep the rigidity of the receiver?

 

[flybynt]

So you think instead of removing i should maybe remove and replace with ones that allow the slides to pass through yet still keep the rigidity of the receiver?

Much better plan if you really have to modify a k gun. Though I think a reverse stretch is really what you want and are shooting for.

 

[dzmedia]

Ok.
So can you please explain reverse stretch to me? I have no idea what that means. This gun is going to be a select fire FA SBR. with a can. So what does reverse stretch mean abd how do I do it

 

[h3pilot]

Here is a thread about what Reverse Stretch is.
http://www.hkpro.com/forum/hk-clone...y-ignorance-but-what-reverse-stretch-gun.html

 

[dzmedia]

Ok..... I think I get it. But why would I want a reverse stretch? What makes,it a better gun?

 

[h3pilot]

Ok..... I think I get it. But why would I want a reverse stretch? What makes,it a better gun?

I think @flybynt meant that a Reverse Stretch gun (like my Z-5RS) is ready for an A3 collapsible stock without needing any alterations. The MP5K was designed for a side-folder stock.
It isn't that a Reverse Stretch is a "better" gun, it is just much easier to put an A3 stock on it.

 

[flybynt]

Ok..... I think I get it. But why would I want a reverse stretch? What makes,it a better gun?

A reverse stretch has the same front end found on a K gun. It can use all all mp5 stocks including the A3 you mentioned, and does not require an adapter or modification to the gun. Uses less pricey and more widely available std mp5 grip frames but is still the same overall length as the K gun with adapter and A3 stock installed you are trying to make. Also the reverse stretch benefits from a longer sight radius and better rear sight drum than the K gun.

The downside to a reverse stretch is it was never made by HK, has a slower FA rate of fire than the K gun, and it has it's own special size recoil rod assembly.

 

[Brad4065]

If you look at my avatar....you'll see the SP89 on the bottom, and the reverse stretch on the top. The stretch later became SBR, by adding a stock and registering with NFA and F/A with a sear, and the bottom became MP5K. They're both great firearms, and you'll love the reverse stretch....I use it literally daily.

 

[jsurowitz]

A reverse stretch has the same front end found on a K gun. It can use all all mp5 stocks including the A3 you mentioned, and does not require an adapter or modification to the gun. Uses less pricey and more widely available std mp5 grip frames but is still the same overall length as the K gun with adapter and A3 stock installed you are trying to make. Also the reverse stretch benefits from a longer sight radius and better rear sight drum than the K gun.

The downside to a reverse stretch is it was never made by HK, has a slower FA rate of fire than the K gun, and it has it's own special size recoil rod assembly.


View attachment 77634

Beautiful guns! The sight radius should be identical between a K and K-RS.

If you look at my avatar....you'll see the SP89 on the bottom, and the reverse stretch on the top. The stretch later became SBR, by adding a stock and registering with NFA and F/A with a sear, and the bottom became MP5K. They're both great firearms, and you'll love the reverse stretch....I use it literally daily.

That looks like a stretch, not reverse stretch. The stretch has a front end that is mp5 fullsize, while the reverse stretch has the rear of the receiver mp5 fullsize length.

 

[JNAP94]

Beautiful guns! The sight radius should be identical between a K and K-RS.








That looks like a stretch, not reverse stretch. The stretch has a front end that is mp5 fullsize, while the reverse stretch has the rear of the receiver mp5 fullsize length.

Never mind him, he is always ass backwards!! ;-)

 

[flybynt]

Beautiful guns! The sight radius should be identical between a K and K-RS.

I'll measure it later to be sure but you are probably right....my mad cow gets me in trouble every now n then.