Does any body know what kinds of suppressors can be used with a Beretta Cheetah 84FS in a .380 caliber?
Also, does the 9 mm short mean the same for a 9mm suppressor?
Any 9mm silencer will function perfectly on a 380 auto as long as it is mounted properly. The 380 auto uses .355" bullets like the 9mm parabellum. The 9mm makarov uses .365" bullets. You are in luck, LA is one of the 37 states that allow unlicensed civilians to own silencers. You will need an extended threaded barrel, but I do not know who makes them for the Cheetah.
But there is a problem. Most blowback pistols of large caliber let out lots of noise when shot. This is because blowback operation results in the action opening while the bullet is still traveling down the barrel. Recoil operated actions delay opening a tiny bit which allows pressure to drop resulting in less noise out of the ejection port.
I put my homemade (on ATF form 1) silencer on my makarov clone. It is loud.