1/24 scale guns

Green frog,hoser is right about the squad rod, also mpc had a few more kits with the same equipment, they are as follows, the joker/goon gothem city police car, the car from the t.v. show t.j.hooker (william shatner ) and the dodge monoco force 440 ,all these can still be found on ebay also try hobby heaven. hope this helps.

Hoser has a great idea and if you only find one, there is always RTV molding in resin for reproductions. Micro Mark has all you need including instructions.

GreenFrog,

Hope this can help, but it might be a bit of a long shot. In 1980, MPC issued a 1:25 Nova police car kit called the Squad Rod, # 1-0744. (I think there might have been another variant as well.)Among the accessories are an M-16, a Thompson SMG, a sawed-off pump shotgun, what looks like an M-1 rifle, a revolver and I believe a tear-gas launcher.
The detail is pretty good, but you will have to scrounge the hobby swap meets or, of course, eBay to find one. Good luck.

My son has some of the 'newer' G I Joes that are only about 5" tall. They come with all sorts of weapons, some may work for what you need. G I Joe was a real man in my day, 12" worth of mean fighting machine, now days he shrunk to a small dude!