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Discussion Starter · #1 ·
Hi everyone. Since I got my MR223 A3 I have been looking for a simple, yet robust minimalistic stock. Couldn't really find any on market except for the plastic thing like Mission First Tactical's Minimalistic stock. But I was more looking for a fixed, non adjustable stock with the shortest length of pull for maximum mobility.

So I started to check out other AR stock manufacturer and the most simple one is the Battle Arms Development stock. Problem is after emails and emails to BAD, they never respond any of my emails. So I started to think of the idea of making my own stock for my new HK MR223 A3 rifle. And with CNC 5 axis machine at hand I could as well just make my own.

I took the BAD minimalistic stock and started to think of how I want to improve that existing design. The way BAD stock is held together is via a hex-bolt and while the clamping force increase the stock will simply "stick" to the HK MR's buffer tube and introduce a "friction hold" between the mating surfaces.

What I want is to remove that hex-bolt and insert a solid pin directly underneath my stock. So instead of a "friction hold" I get a structural interlocking design which is ,per nature, more robust and things can never "rattle loose". The entire package is hold togehter with a transverse going roller pin, as HK are huge fan of roller pins I just kicked in another :)

So basically I got a stock design that is 3 part and much stronger design compared to the BAD stock. The stock and the locking pin are both made of 7075-T6 and hard coat anodized in Mil-spec type 3 black. I just want to share this with you guys and let me know what you guys think of this minimalistic design? The stock is currently made to fit HK buffer tube and sits perfectly with a little wiggle. The wiggle is similar to a Magpul MOE Stock (Commercial variant).

Mission First Tactical Minimalistic stock: 167gram
MAgpul MOE: 226 gram
BAD: 89.9gram
My stock: 89gram (including the pin). Hurray!! I made it! :-D


The only thing it needs now is the anodizing and some shooting. So far it shoulders very nicely and sits perfectly in the shoulder pocket. Despite the all-aluminum design it is actually just as comfortable a my Magpul MOE stock! Amazing! I thought I sacrificed the comfort by going to "all metal". But no! :)
 

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very interesting. looks well thought out and built. good job.
 

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Discussion Starter · #4 ·
Thanks guys! :)

The left image is a foam mock-up to see how it looks like. And then today I finished two of them in 7075-T6 (right image). But once its anodized and installed on the rifle I will post more pictures and go shoot with it.

The design is surprisingly strong. I love the "interweaving" structure. Bald and raw :)
 

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While it's not really my cup o' tea, it is pretty cool as a concept. Kudos to you for setting out and doing some of the hard work on your own. THIS is for you.

From an end-user perspective these would be my concerns:
- can it handle the impact from: mortar/stuck case clearance (not that I've much of this problem in the HK's), buttstock strike, a fall to the deck from 1m? 2m?
- related to the above, will impact put more stress on the thread portion of the buffer tube and what is the chance of having a failure at that point on a gun (both with and without the A5 castle nut)?
- how bad is it going to suck for cheek weld on bare aluminum in cold temps?
- what's going to be on the back end to prevent slipping on slick clothing or kit?

...just some thoughts
 

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While it's not really my cup o' tea, it is pretty cool as a concept. Kudos to you for setting out and doing some of the hard work on your own. THIS is for you.

From an end-user perspective these would be my concerns:
- can it handle the impact from: mortar/stuck case clearance (not that I've much of this problem in the HK's), buttstock strike, a fall to the deck from 1m? 2m?
- related to the above, will impact put more stress on the thread portion of the buffer tube and what is the chance of having a failure at that point on a gun (both with and without the A5 castle nut)?
- how bad is it going to suck for cheek weld on bare aluminum in cold temps?
- what's going to be on the back end to prevent slipping on slick clothing or kit?

...just some thoughts
Good points sir!
 

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Discussion Starter · #8 ·
While it's not really my cup o' tea, it is pretty cool as a concept. Kudos to you for setting out and doing some of the hard work on your own. THIS is for you.

From an end-user perspective these would be my concerns:
- can it handle the impact from: mortar/stuck case clearance (not that I've much of this problem in the HK's), buttstock strike, a fall to the deck from 1m? 2m?
- related to the above, will impact put more stress on the thread portion of the buffer tube and what is the chance of having a failure at that point on a gun (both with and without the A5 castle nut)?
- how bad is it going to suck for cheek weld on bare aluminum in cold temps?
- what's going to be on the back end to prevent slipping on slick clothing or kit?

...just some thoughts

Thanks for the inputs. Thats great someone took time to think through the cons.

- can it handle the impact from: mortar/stuck case clearance (not that I've much of this problem in the HK's), buttstock strike, a fall to the deck from 1m? 2m?

My answer: I haven't tried that mortar impact. The only time I ever did this was on my old SIG 516. A dummy round was stucked and mortar was the only way. But to be honest I think this little sucker can handle pretty much force. The locking pin is a massive almost Ø8mm in 7075-T6 which in yield strength is beyond 500 MPa which is pretty high on the scale compare to forexample 6061-T6 and other steel types. Not the strongest of metal alloys, but one of the stronger options in aluminum. The entire stock is also in 7075-T6 so material to material strength wise should be in balance, one part will not deform another due to yield strength difference during mortar. The entire stock is only 100mm, so the distance x force is lesser compared to a full size stock which in return pays off when mortaring as the force is more "gentle" and puts less stress on the "buffer-stock-locking pin" relation upon contact. But I still believe a classic A-Frame polymer stock will be more mortar resistant than a solid aluminum. But again, the whole purpose is to make it more compact and give more room from trigger hand to shoulder. Its much more spacious now and with that comes some con.




- how bad is it going to suck for cheek weld on bare aluminum in cold temps?

My answer: This is **** in the cold! Not as comfortable as the polymer ones. But I put on some reuseable camo tape and everything is fine and comfy :) But yeah for sure, bare aluminum to cheek sucks!




- what's going to be on the back end to prevent slipping on slick clothing or kit?

My answer: I sketched the stock in a way so the buffer tube is protruding with about 2mm. The slant of the stock's back is not parallel to the slant of the HK's buffer tube this creates two serrations on the back. And the big squared hole in the middle of the stock creates just another "grip" point. So all 3 features acts pretty well. I tried it on my Nike running shirt made of 100% smooth cotton. It has a pretty good "traction". But compared to a traditional rubber piece, naaah.. I don't think its in that league of traction.

But this thing looks freaking cool and much much lighter compared to the Moe/HK's factory stock or even the Mission First stock. Its just simple and makes my rifle look like a submachine gun. :)
 

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- how bad is it going to suck for cheek weld on bare aluminum in cold temps?

My answer: This is **** in the cold! Not as comfortable as the polymer ones. But I put on some reuseable camo tape and everything is fine and comfy :) But yeah for sure, bare aluminum to cheek sucks!

i really like the minimalistic approach and i like your do-it-yourself approach alot! - i already bought the mft minimalist stock for my mr223 a3 11 inch sbr comming in february because i wanted to lighten up the gun -

ever thought of putting a small neoopren sleeve over the buffertube? you just would have to sow it very narrow so that it fits over just right and stretches the neopren just a bit? - would be nicer for shooting (cheeckweld) and for protecting the surface of the buffer tube?
 

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ever thought of putting a small neoopren sleeve over the buffertube? you just would have to sow it very narrow so that it fits over just right and stretches the neopren just a bit? - would be nicer for shooting (cheeckweld) and for protecting the surface of the buffer tube?
ACE stock did something similar with their design, but it was foam and it was not up to the task of hard use (Sweat + sun then cold + moisture). OP's idea reminds me a bit of the ARUL a bit, but with a more positive mounting design.

 

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Discussion Starter · #11 ·
i really like the minimalistic approach and i like your do-it-yourself approach alot! - i already bought the mft minimalist stock for my mr223 a3 11 inch sbr comming in february because i wanted to lighten up the gun -

ever thought of putting a small neoopren sleeve over the buffertube? you just would have to sow it very narrow so that it fits over just right and stretches the neopren just a bit? - would be nicer for shooting (cheeckweld) and for protecting the surface of the buffer tube?
I have foam on my tube. But as the other guy said, foam is not ideal for hard use. I think the best is the reusable tape. Extremely low profile and cheap solution.

I think the next project would be to make the HK bolt, I just need to identify the correct alloy for this stuff. Anyone knows?
 

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Discussion Starter · #12 ·
Firearm Gun Rifle Assault rifle Trigger

Ok the stock came back today in hard coat anodize black. Looks pretty good and I'm very happy with the result. The fit and finish is superb and pretty light weight too!

See picture. Its now fully mounted on the rifle.
 

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View attachment 80153

Ok the stock came back today in hard coat anodize black. Looks pretty good and I'm very happy with the result. The fit and finish is superb and pretty light weight too!

See picture. Its now fully mounted on the rifle.
Well done. However, from the practical standpoint, the stock not only lacks butt pad, but it also lacks any means to install one. Screw holes, matching the hole pattern of any popular commercial off-the-shelf butt pad (Magpul butt pad comes to mind), would significantly enhance the modularity and performance of the product. I suppose it's something that can be done at this point of development.
 

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Discussion Starter · #14 ·
Well everything can be done...at any stage. I got full control :)

I designed it like it is here because I like the raw and simplicity of it. Its amazing so light this rifle is and very "roomy" as the entire space is now cleared near the buttstock.

Funny thing is I got a Magpul MOE. Studied it and notice there are serrations on the plastic stock's bottom end if you remove the rubber. So I also pulled that off! He he he...I like things simple. No screws working loose or anything :)
 

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It looks great.

As for HK bolt alloy, there was a post last year that gave a HK alloy spec but I think it was for the barrels. I have a link to it on one of my iPads. When I can I'll track it down and post it here for you and/or PM it to you.

Once. Again, end product looks great!

David
 

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Discussion Starter · #16 ·
It looks great.

As for HK bolt alloy, there was a post last year that gave a HK alloy spec but I think it was for the barrels. I have a link to it on one of my iPads. When I can I'll track it down and post it here for you and/or PM it to you.

Once. Again, end product looks great!

David

Nice. Please :)

Are you the Regular Guy from youtube?
 

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Discussion Starter · #19 ·
Got it! Thanks! Had it confirmed through another article that this Aubert Duval is what they use for barrel blanks. But couldn't fine anything about hte bolt steel alloy if they were using the same alloy or not.

Is there a market for aftermarket HK416/MR223 bolt heads? HKparts don't even carry them in their product portfolio.
 

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Got it! Thanks! Had it confirmed through another article that this Aubert Duval is what they use for barrel blanks. But couldn't fine anything about hte bolt steel alloy if they were using the same alloy or not.

Is there a market for aftermarket HK416/MR223 bolt heads? HKparts don't even carry them in their product portfolio.
i saw that you are from europe because you have the mr223 - i think you should look into the legal framework of your country first - here in switzerland bolt and bolt-heads and barrels and bare-uppers are considered a ''wesentliches waffenbestandteil'' - weapons parts that are restricted - you need a special licence for producing and selling and buyers need a special licence if they do not change the part directly out by a licenced arms dealer ( when you want to buy an ar15 bolt-assembly without getting a WES you have to hand-over the old used one to get the new one or otherwise you need a new WES)

you could get into lots of troubles if you start producing and selling restricted weapons parts
 
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