A concealable, single-shot grenade launcher, the BP-02 "Pup" offers explosive firepower while retaining portability. The Pup functions mainly as a pistol, and strongly resembles a revolver. It fires the same grenades as the M327 Grenade Launcher, but with a grossly reduced size and ammunition reserve. It appears only in Killzone, and not its successors.
The Pup looks almost identical to a revolver, but lacks the iconic six-shot clip. Instead, to reload the entire barrel is folded down, the grenade is entered directly, and the barrel is flipped up again. It is manufactured by the Helghast, but is never used by them in-game, and is only found lying around in certain levels.The Pup fires grenades in the same manner as the Grenade Launcher, but does not reduce movement speed. It should be used while in cover, as you will need the time to reload. Do not rush into a room full of enemies with it equipped, as you will most likely fire one shot and just die. Instead, stay by the door and fire individual shots into groups of enemies to save ammunition. It is also very effective when firing over cover, as its large gravity drag means that a well placed 45°shot will kill any enemy on the other side of cover.Try not to prioritise the Pup as your main weapon, and instead treat it as a sidearm in difficult situations. When available, drop it for the larger Grenade Launcher due to its larger ammo reserve and rate of fire.

The M327 Grenade Launcher is the ISA's one and only grenade launcher manufactured by ISA Laboratories. It fires timed explosives from a six-round drum, which are useful for blanketing an area to deny enemy access, or for taking advantage of the chaos of a distant firefight. The weapon is also very effective at knocking out enemy positions at medium and long range, at ground level or elevated positions.
The "Thumper", as it is nicknamed, fires 40mm percussion grenades that detonate on contact with soft matter such as flesh, but otherwise have a short delayed detonation. The grenade is relatively bouncy so it can be ricocheted around corners and into rooms for easy breaching and its extremely effective with enemies behind cover.Grenadiers, also known as "grenade jockeys," are equipped with these, as is the Assault class in the multiplayer.

The StA2 Battle Pistol is a grenade launcher-like pistol that increases grenade storage capacity and fires grenades farther than a soldier could ever throw. A modified variant to the less effective BP-02 Pup Grenade Launcher. With a less likely accidental detonation rate and slicker reloading design it proved to become a mainstay for most soldiers fighting for the Second Extrasolar War.