Zombie Panic! Source

Glock 17

It holds 17 rounds. Baseline pistol in the game.

Glock 18C

Is almost identical to the Glock 17. Unlike its real-life counterpart it does not fire fully automatically.

Heckler and Koch USP 9mm

Slightly more powerful than the Glocks. In-game name is "USP".

Walther PPK/S

It is incorrectly shown to have a slide release when reloading, and somehow uses 9mmx18 pistol ammunition even though this gun is chambered for .380 (9mm Kurz or Short). Slightly weaker than the other pistols. In-game name is "PPK".

Taurus Tracker 455

It is a six-shot .45 ACP caliber Taurus revolver which uses magnum rounds (.45 ACP). In-game name is "Revolver". It incorrectly holds 6 rounds when it really holds five.

Remington 870 Shotgun

A pistol grip shotgun that holds six rounds of shotgun ammunition. Called the Remmy 870 in-game.

Winchester Double Barreled Shotgun

A double-barreled shotgun, slightly more powerful than the Rem 870.

Serbu Super Shorty

Holds 3 shells. Called the "Super Shorty" in game.

AK47

Holds 30 rounds.

M4A1

Holds 30 rounds. Called the "M4" in game.

MP5A4

Holds 30 rounds. Has a 4 Position trigger group. Incorrectly uses "Rifle Ammunition". Called the "MP5" in game.

HE/ Frag Grenade

HE Grenade shaped like an M18 Smoke Grenade. In-game name is "HE Grenade", but on the model itself the words "Frag Grenade" can be read.