ORIGINAL: jsb57
I can not find it but a few years back there was a company that made an over/under which was basically an AR with a 12 gauge mounted below it like a grenade launcher would be.
Yes there was one and it is called a "Crossfire" It's a 223 under a 12 ga pump shotgun. The 223 loads from a magazine. The 12 ga loads from a cylinder running through the stock. There were only about 1500 made. I understand the 223 is not too accurate.
OB