Lots, if you mean the weapons known as revolvers, rifles, pistols (semi-automatic, automatic), and cannon (artillery, phalanx, anti-aircraft, etc.) otherwise referred to by non-professionals as guns
Generally the categories above are firearms as they use a percussion technique to discharge.
Then there are the various calibers referring to the shells (a.k.a. bullets in the smaller ones). There are quite a few of those.
There are also a number of different brand names.
I think the question needs to be revised
