http://www.world.guns.ru/assault/as69-e.htm

A real-world russian example!

hah well if that aint just the darndest thing I ever did see I wonder why they developed it though... There can't be much demand for aquatic warfare out there surely...

There are also a couple pistols which were developed for underwater use:

SPP-1 underwater pistol (Russia)

Glock 17

Underwater guns were developed for Special Forces (such as the Navy Seals, etc.) and suffer severely from limited lethality range both above and below water. As you can imagine, as depth increases the range decreases due to water pressure. The max lethal range of the SPP-1 is 17 meters at 5 meters underwater and 11 meters at 20 meters. Better than going at it hand-to-hand, but still a waste in my book.

Note: you can fire most guns underwater. Unfortunately, it is usually a one-shot-deal. The gas produced is responsible for pushing the empty out of the barrel, but at depth the gas bubbles away and the empty will most likely get jammed.

- Zombie

revolvers sound like they should be fine, as long as the rounds were sealed well from water,

although from what I've seen, normal bullets just aren't meant to go through water

And how far do you actually see under water? Not that many meters... so quite effective for their intended use, I imagine.

Didn't those Heckler 'n Koch guys invent a submerged gun, too?

hi everyone.i am hooked to xcom games.and i am verry happy with this site.
in the deltaforce pcgame you can fight with an underwater pistol and submachinegun.but the weapons were weak.much greetings from DEFCON,

Well greets DEFCON /never played the old Deltaforce games much but I do agree on the XCom side of things, they are awesome games

Its a good point though that visibility is similarly restricted to weapon range and lethality... I guess everything does kind of come around full circle really!