So I'm watching Predator tonight on AMC, and I see that the Indian guy (Billy, I think) had a shotgun mounted under this M16 where you might normally mount a grenade launcher and it got me to wonderin'.

Would it be legal to take the stock off of say a Mossberg 500, put an 18" barrel on it and mount it under your AR-15? I only ask because it's late and I'm bored.

It should be, but it kinda depends on how the ATF sees it. If they consider the rifle stock to be the shotgun stock as well, no problem. If not, it is probably illegal.

The NFA specifies a minimum overall length for shotguns.

min 18" barrel with an overall length of 26" or 27".

Never measured a pump gun to see what the receiver length would be.

your reciever has to be in excess of 8 inches, i think when i measured mine in iraq it was like 7.75 inches, but i don't remember,

theres a company, i think there name is sage something that does make a 3 shot pump that mounts just like a m203, but its way short, and definitly a nfa thing.

from what ive heard from poeple who try to do this the biggest problem is with the recoil on the front of the mag well, apparently it can fuck up your lower reciever somehow.

Doesn't the ATF consider an over/under style gun that shoots rifle caliber from one barrel and shotgun from the other an AOW?

www.gddinc.com/knights_masterkey.html

Its a $200 tranfer tax, NFA rules apply for this.

Quoted: Doesn't the ATF consider an over/under style gun that shoots rifle caliber from one barrel and shotgun from the other an AOW?

I would doubt that only because I've seen many of them and they weren't Title II firearms.

Quoted: Quoted: Doesn't the ATF consider an over/under style gun that shoots rifle caliber from one barrel and shotgun from the other an AOW? I would doubt that only because I've seen many of them and they weren't Title II firearms.

Ditto. Perfectly legal. Just make sure you adhere to the longer length requirement...meaning make sure both barrels are 18". Legally, only the shotgun barrel need be 18, and the rifle 16, but it's probably alot safer to keep em  both the same length.

Also remember, most Mossy's have the safety mounted on the tang of the receiver, if you mount it on an AR, you won't be able to access it.

A Remington 870 would work better, since the safety is on the trigger guard.

Any other weapon. - The term "any other weapon" means any weapon or device
capable of being concealed on the person from which a shot can be discharged through
the energy of an explosive, a pistol or revolver having a barrel with a smooth bore
designed or redesigned to fire a fixed shotgun shell, weapons with combination
shotgun and rifle barrels 12 inches or more, less than 18 inches in length, from
which only a single discharge can be made from either barrel without manual
reloading, and shall include any such weapon which may be readily restored to fire.
Such term shall not include a pistol or a revolver having a rifled bore, or rifled
bores, or weapons designed, made, or intended to be fired from the shoulder and not
capable of firing fixed ammunition.

According to the actual rule on an AOW, as long as the barrel is not between 12"-18", it is not classified as an AOW. This is my interpretation at least.

Kris

Quoted: Also remember, most Mossy's have the safety mounted on the tang of the receiver, if you mount it on an AR, you won't be able to access it. A Remington 870 would work better, since the safety is on the trigger guard.

get cav arms replacement butterfly sagety, on the sst590 the rail comes over the safety so they had to design a new one. works awesome, and is still ambidextious.