I posted this over in the Shotgun Armory section.  Thought it might be good over here.  

http://farm5.static.flickr.com/4052/5130555084_2a07b40671_b.jpg

I don't own the Benelli M4 but I understand that the buffer tube protrudes at an angle that would not make this possible.  If Magpul did make something like this I would own a M4.

That's cool. The M4 does need better stock options.

The Mossberg 930 has the same problem.  I wouldn't mind a pistol grip stock on mine, but the only option right now is the Choate one that looks kinda like ass.

That looks sweet.  I'd be all over that...mine needs some magpul love.

I would buy it.

I'm in for one or two.

Now that is awesome...!

I don't think the angle would be the problem for this design. Rather, the length of the recoil tube is the stumbling block.

The length of the tube would make the design you show too long. Fully collapsed, it would be just slightly shorter than the OEM stock (which is too long for many tactical applications). If one were to adapt this design such that the recoil tube could fit almost all the way into the rear of the buttstock when fully collapsed (leaving just enough additional length so that the tube doesn't impact the shoulder during recoil) then you might have something.

Overall, I love the idea. I think it is totally doable. Just not with the length and thick buttpad your illistration shows. The number one motivation for M4/M1014 owners looking for replacement stocks is LOP. It needs to be shorter. That's why those shotgun accessorizors over in California are going to sell a metric tonne of those new fixed stocks. If you can make it collapsible to the minimum length and extend it to OEM length, that's a huge plus. If you can adapt the Magpul-style cheek riser, that's also a huge plus. If you can do them both, some scattergun fans are going to go completely bonkers for it.

I'd definitely buy one for mine RELEASE DAY.  Bring it MagPul.

I made a few modifications.  They fully extended stock should be slightly shorter than the factory stock.

http://farm2.static.flickr.com/1434/5137628923_980d4dc659_b.jpg

Here it is with the stock fully collapsed

http://farm5.static.flickr.com/4056/5137658197_fa4c51103c_b.jpg

I am at the edge of my photoshop ability so there isn't much more I can do with stretching and pulling on the magpul stock.  

Has Magpul considered working on a collapsible stock for the Benelli M4?  (Drake can you comment?)  I know it's not as easy as mocking one up in photoshop but there would be a lot of interest in another option.

Oh my gosh that's SICK.  How on earth can we get this to happen before I die?  WANT NOW.  Cannot stand the stock, stock.  Definitely needs the nice fat rubber pad as pictured, too.

PLEASE OH PLEASE!  I'd buy one for $400 if they made it today.  I could also drop a case size too!

Not to shit on your parade, but I thought that the weird "tube" protruded at a steeper angle, putting it "below" your stock axis there.  Though, since it wouldn't be "hitting" anything if it poked below the "foot" on that stock, I don't see how it'd be a huge issue?

An M4 stock needs an adjustable cheek riser and it needs adjustable length of pull.  The ACR/Masada stock would give you just that.  If they could make the internals work with the Benelli recoil tube, it'd be PERFECT.

This is one of those things that just needs to happen. I'd buy the gun just to get that stock on that gun.

That looks awesome!

Wouldn't be an issue. The steeper angle than his illustration shows would affect aesthetics, but it wouldn't make any difference as far as function.

As far as how this would mate-up to the receiver, it should be a one-peice stock/pistol grip that screws on the same as the standard pistol grip stock. This wouldn't be a separate stock and pistol grip like the Benelli "skeleton stock" is. This makes installation very easy, and you'd get all the functionality of the wonderful ACR stock on your Benelli M4. It's a sweet concept. And, if it could be done cost-effectively, it would be wonderul. It seems though, that accessory manufacturers don't feel that there are enough M4 owners out there with the desire to buy a second stock. As an M4 owner myself, and someone who frequents the Benelli forums, I can say that this is a misconception. The popularity of the Benelli M4 in "tactical" circles, its stock's excessive LOP, and its import status make a quality US-made stock highly desireable. Given the proper marketing, a very large percentage of Benelli M4 owners would bite on a Magpul stock like this. LEO's (police officers; not guys who go by "Leo" like me) would probably be very interested as well.

make it fit the M1 and M2 and M4 and you can put me down for 3

What, no luv for the M3?!