.308 AR Shotgun Upper

[Newbie22]

Hi All,

I apologize in advance if this falls in the shotgun category rather than in rifles.

I remember way back when I was reading a thread on this forum discussing the possibility of a shotgun upper for an AR-15. One of the big technical hurdles was the limited size of the magazine well, which meant standard 2 3/4" shells wouldn't even be able to fit.

But now that I think about it more, what if a shotgun upper were built off a .308 lower? A quick google search lists the overall length of a .308 at 2.8", just enough to clear a shot shell. Now, the width of the magazine might be problematic, so it may have to be either single stacked or limited to a certain gauge, but is this idea feasible? What other hurdles could there be that I'm not foreseeing, and how might we get around them?

Thanks!

 

[USAF_Vet]

If you want an AR shotgun, I would recommend buying one that was designed as such from the factory rather than trying to Frankenstein one together.

The MKA-1919 seems to get decent reviews, but I have no personal experience handling one myself.

 

[adelbridge]

you would need a redesigned upper and barrel. Have a look at the Benellli M4, it is milspec and would run circles around an adapted AR.

 

[MilliradianDOT]

You've tweaked my interest here. Though there are other options available, this is how innovation works! The idea that you could have one lower that goes from battle rifle to DMR to door kicker and then to clay shooting gun is quite interesting don't you think?

I am no engineer but I live with a mechanical engineering student and I have gone from looking at guns as weekend entertainment, self defense, and other things to seeing them as the amazing machines they are. So why wouldn't this work?

From a little research I have found this:
The inside width of a FAL magazine is .998 inches. The 12 gauge shotgun shell rim is around .810. Rock River's LAR-8 takes FAL mags so the lower should work. Maybe with a modified follower, you could put four or five rounds of 12 gauge in a FAL mag.

As far as the upper, once again, not an engineer. But why couldn't it work? They have .50 BMG uppers for AR's. I am sure someone could work something up. Custom shops work up crazier stuff all the time.

 

[RPRNY]

Soon to be featured on "Sons of Guns ", no doubt. This is a Red Jacket disaster (project) if ever there was one.

 

[Silverbullet555]

Go check out weaponsguild. They are working on a 12 gauge upper for a .308 lower.

 

[adelbridge]

The inside width of a FAL magazine is .998 inches. The 12 gauge shotgun shell rim is around .810. Rock River's LAR-8 takes FAL mags so the lower should work. Maybe with a modified follower, you could put four or five rounds of 12 gauge in a FAL mag.

You would never fit a 12 gauge barrel into a stock upper receiver. It would take a custom BCG. You are talking major investment in a retail market that may be drastically different in just a few months. Military could have backed such a weapon if it was feasible.

 

[stubbicatt]

There is an AR look alike shotgun which has apparently caught the attention of the 3 gunners, MKA 1919. I think USAVet mentioned it in his post.

From what little I have learned about it, it shares very little in common with the AR series other than an external resemblance. The internal workings are quite different.

 

[-v-]

But, this is a do-able project, by all looks. The main thing is it would need a completely custom upper receiver to accommodate the 12ga barrel and the necessary bolt to feed/extract the shells. Feeding could be through modified FAL mags or modified steel SR-25 pattern magazines, depending on the lower of choice.

If someone has time and a machine shop, entirely do-able, but it would be pricey.