I've been thinking about this a lot, and wondered if any of you guys have done this??? Also, any lead on those metal hand guards, the ones that cover the barrel with the M203 GL and bayo lug mounted shotties. Was thinking a 604 w/ this setup, not sure on the type of shotgun yet.....

Bayonet lug mounted shotgun? I've only seen the KAC Masterkey mounted on AR's.

I could be wrong with the way it mounts, but i'm thinking of something totally different on a rifle, not carbine. The shotgun is also mounted closer to the bottom of the barrel and partially shrouded.  The BEST picture I can think of, is in the movie Predator .......The tracker "Billy" has one. I'm gonna try and dig up a picture.



best picI can come up with on short notice....

this?






That is a ~16" Mossberg 500, and it would be pretty darn front-heavy...



 

There is indeed another type of mount. It mounts to both carbines and rifles.






This rifle is airsoft, but you get the idea:




And the Predator gun (not a Masterkey):




I think that the one in Predator was just something that the movie directors rigged up.

That's not quite the same setup as Billy's, see above



 

You can even see the hollywood blank firing flash hider thingy in the flash hider.  Causes the weapon to cycle even with only the pressure from a blank.



 

Yeah it would be very front heavy but, I was thinking of doing it for more of a conversation piece.  I talked to some guys that were in the special forces in the 70-80's and guys talked about how they rigged shoguns to their 20 inch M16's.

I guess my question is "Why?"





The only practical application that i can see would be for door breaching.


They named the Masterkey the Masterkey for a reason.





You'd be going from a light fullauto/burst rifle with 30 rounds to an awkward-handling pump shotgun with 5-6 rounds, while weighing down your primary weapon.





If it's a movie-buff thing or a conversation piece, go ahead.



ETA:  I'd much prefer something like a Serbu Super Shorty or a standalone Masterkey for breaching duty, on a short bungee sling.  Fire one handed with your offhand and your primary weapon in your strong hand, drop the breacher and keep moving





 

I can use it for hunting,the rifle for furry game and scatter gun for birds.Then there is the zombies of course.You can get scatter gun flares I suppose.Novelty idea but I really don't see a general purpose for it that a stand alone scatter gun can't do.

The mag with spring and follower wont hold that many rounds. Btw, you wanna breach doors, try a Tromix full auto.
http://www.tromix.com/Welcome.htm

Huh? It's the same picture. The ones pictured earlier in my posts are KAC Masterkeys. I said that I believe that the one used in Predator was something rigged up by Hollywood.

A standard Mossberg 500 will hold 5 in the tube and 1 in the chamber, if your rounds aren't extra-long like some brands are...



 

The one IN THE MOVIE was a ~16" Mossberg 500, with a slick-side A1 upper and a straight delta nut.
The one you posted of the gun in the case was an 870, had a detachable carry handle and a conical delta nut.
This is what you posted:

This is from the movie:

It's close, but not quite the same.
ETA: i think i see what happened, you hotlinked a picture that is now dead, so it doesn't show up in your post.





I also meant to quote the picture that i posted in this post just above, not the dead link.
This link:  http://www.arniesairsoft.co.uk/projects/scifi/billym16.jpg





leads to a "403 forbidden" error.  If you can still see it, it's only because it's in your cache or requires a login...
 

Yes, you're right. I think when the picture went away, you saw the wrong one.

The airsoft gun in the working link is a Masterkey replica, NOT the same as the Predator gun, which I believe to be rigged up by movie directors.

Twas all a misunderstanding.

While this is an EXCELLENT idea, I must warn you that you are moving into the realm of NFA. A short barreled rifle has a barrel less than 16" while a short barreled shotgun has a barrel less than 18". Unless you dont mind having your 18" barrel stick wayout in front, go ahead and mount up. There are also Any Other Weapons (AOW) that are a $5 transfer tax (Serbu super shorty is one) that are a shotgun reciever that has never contacted a full stock in its existance, only pistol grip. DO NOT buy one of these and put it on an AR15. Once you do that you are firing it via the shoulder stock of the AR and have an illegal SBS. That is a ticket to Club Fed. You might be able to get a virgin receiver from Remington or Mossberg that has never had a shoulder stock that you can make into an AOW, but it will cost $200 and be put on a Form 1, for that route you are better off buying an SBS and you can also put a full stock on it. If you desire the shorter version, you will have to get an SBS and pay the $200 tax stamp. The NFA forum has more info on this mod, I got this info from my Class III dealer when the same thought crossed my mind. If you want to do it, go for it!

When someone asks you, "Why do you want to mount a shotgun to an AR15?" your response should be, "WHY NOT??" or "You just answered your own question!"

I remember these from back in the 80s.  I think I remember seeing them advertized in soldier of fortune magazine sometimes.  I thought they were really cool as a kid.  Yes I read SOF as a kid, not so much now that I have been around to some of the countries they used to write about.

That mount looks exactly like what I am looking for! Who makes it???  

I'm pretty sure that Knight's Armament does.

OK...I'm looking at the shotgun action mounting...and as a machinist, I am not at all happy with it...  



I see only 4 hex head cap screws holding a 12ga shotgun to an adapter mount...That's a lot of strain on 4 little screws...  

Like he said, KAC.  And anytime you want to do anything with a firearm, Zombies are always a good reason.

Alright, even if you do come across the KAC mount, will it fit a lightweight barrel? It's made to fit onto the M203 cuts and gov't profile portion of an M4 barrel. Are they the same diameter? I'm not sure, but I don't think they are.

I thimk what you would want is a My65pan shotgun mount...If you were really serious about mounting a cut-down 3-shot shotgun under your AR...  

The Predator mount is the one that JA Ceiner used to market in the 80s/90s.  It mounted to the bayonet lug in the front, and had a rear bracket that mounted through the front pivot pin.

Some more pics and info here:  http://shotgunworld.com/bbs/viewtopic.php?f=7&t=86933&start=0

Just like an M203... If you use a non QD mount it will fit a 605, M16, M16A1, M16A2, 723 with notched barrel, 727, M4, or similar. If you use the KAC QD mount you will have to use an M5 RAS on the rifles to get it to work. It will only fit a carbine with a lightweight barrel with a special mount made or a sleeve put on the barrel between the mount and flash suppressor.
ETA: The Masterkey mount is not sold seperately. If you want one you will have to purchase the SBS from KAC ($), cut up an M203 ($), or make one from scratch ($).
Dustin