Might be part of a model designation. Might stand for front site.
FS charge
fs=fashion show
Fs can mean For Sale, Full Size. Do you mean SF? Square Footage.
It means full screen FS full screen
For sure.
Automatic Colt Pistol
You don't specify if you mean long guns or hand guns, civilian or military.
hand guns , long guns, Air guns , Rifle these are used as a firearms .
Depends on the maker. Could mean 12 long guns and 25 hand guns or could mean an interior that could hold 12 or 25 long guns.
For sex :)
fs may refer to sampling frequency which is the frequecy used to sample an analog signal.
Long guns and hand guns.