The look-alike under-barrel launchers for the ARs are (or, at least, used to be) 30mm, as opposed to the 40mm of the real M203 grenade launchers. IIRC, the only rounds they could fire were flares, but I don't recall ever handling one.
Yikes! So we're talkin' totally different animals from a standard flare gun then (12ga is approx 18.5mm).
I think so, although I'm dredging up memories from more than 25 years ago. They kind of fell out of favor after the passage of the It's a Crime, Bill in '94.
I have seriously thought of making a trap door in my hood that pops up with a solenoid. Then a semi auto of some kind .22LR or 12 gauge comes up into view. I could fit it under the hood of the 57. I do not think it would be hard to make. I would need a cattle catcher front bumper deal and all flat blacked out car though to make it chime together. I am waiting on MAD MAX days to be upon us then it's happening.
I could easily classify my Beretta NEOS Carbine as a novelty gun,,, It's way cool looking and fun to shoot,,, But it's really only minute of beer can at 50 yards. Aarond .