The following weapons were used in the video game Postal 2
The main pistol is a Desert Eagle, presumably in .50 AE, which has good range and accuracy, and can kill most targets in two or three hits. It is named on signs in gun stores as the "Old Faithful combat pistol", but is otherwise referred to generically as the "Pistol". Ammo is extremely easy to come by as it is the only pistol used by NPCs, being that it was the only one in the game before its 2012 rerelease.
The second available pistol in the game, added in patches after the game's digital rerelease in 2012, is a non-compensated Glock 18 with selectable fire rates of Single, Full-Auto, and Burst. Its non-burst fire modes make it somewhat comparable to both the Desert Eagle and M16, and the two modes differ from their competing weapons in generally the same way: it competes with a faster rate of fire (less delay between semi-auto shots and a higher full-auto rate) but less accuracy (with semi-auto still being rather accurate, but full-auto reaching the kind of spread you'd expect from a shotgun). Accordingly, as it is trying to compete with two weapons at once, it features double the maximum ammo of either weapon. While it has three fire modes, the selector is only modeled to switch between two; when switching from full-auto to burst fire, the selector will flip itself back to the position for semi-auto before the Dude puts it back where he already set it. In Paradise Lost, Habib's automated vendors identify its ammunition as .45 ACP, presumably as a half-hearted attempt to explain why it and the MP5, the ammo for which is properly noted as 9mm, do not share ammunition.
Added with the 2015 DLC Paradise Lost, the Colt Python, referred to as simply the "Revolver", is the third available pistol. Compared to the Desert Eagle, it has a slightly lower rate of fire and holds a hundred fewer rounds in total (not to mention ammo being incredibly scarce, as no NPCs use it, only a handful of pickups exist or are added with each new day, and it cannot be purchased from vendors until Thursday), but competes with noticeably higher damage (enough to generally kill citizens in one shot and lawmen or other armored foes in two or three) and no degradation in accuracy like the Glock. It also features an "execution bar" that fills via killing enemies, which allows for enemies to be marked by holding the secondary fire button and passing the crosshair over them; releasing the button will cause the Dude to deal instant-kill headshots on every marked enemy in his sight, assuming nothing has come between the Dude and a target to obstruct his shot. Its inclusion fits a minor Western theme present in the expansion, what with the old police being replaced by Wild West-style lawmen; as such, the Dude treats the weapon like an old-West revolver, with lots of spinning in the drawing and holstering animations, cocking the hammer after every shot as if it's single-action-only, fanning the hammer for secondary fire, and blowing smoke out of the barrel before giving it another spin if at least four enemies are marked and killed with the secondary fire.
Remington 870 Police Folder
The main shotgun in the game is a Remington 870 Police Folder with an extended magazine tube, a black foregrip, and a Mossberg heat-shield. Signs in the gun store and Habib's vendors in Paradise Lost assign it the moniker "Mansweeper Riot Gun", but like the Desert Eagle, pickups and other sources refer to it generically as the "shotgun". It is a twelve-gauge shotgun with a powerful punch which can blow someone's head up with a single close-range shot. Cats found in-game can be used as an effective "silencer"; accordingly, since cats have nine lives, they will fly off the barrel and gib on impact with whatever surface or person they first touch on the ninth shot.
Unknown Sawed-Off Shotgun
The second available shotgun in the game, added after the game's Steam rerelease, is an indistinct-model sawed-off shotgun which can usually be found in the empty stores of the Paradise Mall. Very powerful at close range, it is able to blow people in half with ease even beyond the range that the Remington can deal headshots and is still an instant kill on most enemies for a decent distance beyond that; in return for this, it has a drastically widened pellet spread, which removes much of the middle ground between completely maiming someone and everybody next to them in one shot and barely tickling them, and its nature as a double-barreled weapon means it requires a reload after every two shells. It is the second weapon added to the game to require reloading, after the Napalm Launcher included in the original release, and is the first which holds more than one round between reloads and which can have a reload triggered early via the otherwise almost-entirely-unused secondary fire function.
Winchester Model 1887
Added to the game with Paradise Lost, the Winchester Model 1887 is the third shotgun available. It features a tighter spread than the other shotguns, allowing for one-hit kills at a longer range, but in return it has a slightly lower rate of fire as, like all video game 1887s, the Dude rechambers the weapon by flipping it via the lever around his fingers à la Arnold Schwarzenegger in Terminator 2: Judgment Day. This ignores the fact that, also like all video game 1887s, the weapon has a standard lever and would break the Dude's fingers sooner than it would let him rechamber it in this manner.
Yet another new shotgun, this time seeming to be a short-barreled Franchi SPAS-12 with the stock removed and a wooden foregrip, also featuring a relocated ejection port moved closer to the top-left corner of the rusted receiver; the model is taken from the game's famous "Eternal Damnation" mod, and its presence in the game seems to be an easter egg, given that it can only be located in a secret area that requires a tough fight against, of all things, velociraptors. It is referred to by the new weapon-selection menu added in post-Steam-release updates as the "Beta Shotgun", indicating that this was meant to be the original shotgun model before the more-polished Remington model was created. Unlike the other shotguns, it does not feature appreciable differences in pellet spread or fire rate to the regular shotgun; it does, however, feature much-improved damage, to the point that even the more bullet-resistant lawmen are guaranteed to lose their head in one reasonably-close-range blast. Like the double-barreled shotgun, it requires a reload after a certain number of rounds (six in its case), but the gun features an incredibly bizarre and silly reload animation wherein the Dude attempts to forcibly shove all six shells into the ejection port at once, only fitting one while the other five go flying; this nevertheless completely fills the weapon.
An M16A2 converted to fully-automatic is the sole automatic rifle in the game, and prior to patches from 2013 on was the only automatic weapon at all. It is not given any sort of overly-aggrandizing name like the Desert Eagle and Remington (advertisements in gun stores instead simply telling you "you know you wanna"), and is simply referred to rather generically (and incorrectly) as a "Machine Gun". It has a medium-powered punch, and can take down gangs easily, though it is rather inaccurate past mid range and has a relatively low rate of fire. The cat-silencer can be used on this weapon as well, though again it will only last for nine shots - which, given the automatic fire rate, means the player will use it up within a second or two. The in-game rifle also comes equipped with a Pachmayr Vindicator pistol grip.
Heckler & Koch MP5N
The MP5N is the second 'assault weapon' in the game you can acquire. Behaving similarly to the M16 with a faster rate of fire, it's medium powered, but can't accept the cat-silencer. Unlike the differences between the starting Desert Eagle and the later Glock above, the MP5 holds the same amount of reserve ammo as the M16, and can often be found utilized by NPCs, particularly in the Paradise Lost expansion. In a surprise design choice, you can switch the weapon from full-auto to semi-auto; the Postal Dude will actually adjust the selector switch to accommodate the player's choice.
The M24 is the only sniper rifle in the game. The rate of fire is exceptionally slow and the gun is nearly useless without using the attached scope (accuracy is severely lowered when firing without it). When being used by the player, the model is reversed, with a left-sided bolt handle.
M26 hand grenade
The M26 hand grenade is the game's sole type of grenade, with an effective blast radius. Grenades operate on a standard five-second timer upon being thrown, though they will detonate instantly upon contact with an actual person. The grenade can also be placed on the ground to act as an improvised mine with secondary fire; as when thrown normally, the grenade will remain inert until someone walks into it, whereupon it will detonate (if anyone other than the user walks into it, despite the fact that the Postal Dude does not pull the pin before dropping it) or it will be returned to their cache (if the user walks into it). Grenades, both thrown and dropped, can also be kicked around, but some care needs to be taken as the grenade can only be kicked about three times maximum before it will simply detonate upon being kicked again; this almost never comes up when thrown for the simple fact that the player is the only one who can make extensive use of kicking (NPCs are only programmed to kick corpses out of their way, assuming they don't react to the presence of one by panicking), but can be an issue in trying to set traps without alerting a potential target by letting them see the player holding a grenade.
This is one of the two rocket launchers in the game. It launches slow-moving rocket-propelled grenades that can home in on targets. A darker-green variant with an M26 icon in place of the fuel-charging meter acted as another variant of the grenade launcher in the now-defunct "Share the Pain" multiplayer component; like the below M79, it simply launched the same hand grenades as the player could throw, acting as a faster manner of getting them out and heading towards a group of hostiles.
M79 grenade launcher
An M79 Grenade Launcher, as typical referred to generically as the "grenade launcher", is one of the three explosive weapons in the game that you can acquire, the only one of the three with a reloading animation between shots, and the only one of the three to be added post-release. Although the reload animation shows the Postal Dude loading in a correct 40mm grenade, the actual shot that comes out of the tube is the model for the hand grenades and behaves just like them, complete with bouncing harmlessly off of surfaces before coming to a rest and exploding a short time later, and only instantly detonating on contact with something if that something is another person (as such also ignoring the minimum safe arming distance of a real 40mm grenade).
M18 smoke grenade
A new throwable weapon added with Paradise Lost is the M18 smoke grenade. While most games are content to have the M18 release incorrectly-colored smoke, Paradise Lost goes a step further and completely misconstrues its intended purpose, turning the grenade into a flashbang. It is utilized in the same manner as the usual frag grenades and other thrown explosives, the only difference being that enemies nearest the explosion will be stunned for a few seconds, while those a bit further away from it will generally panic.
The Napalm Launcher is the last weapon in the 'launcher' style of guns in Postal 2 and also the only gun in the game not based on any real-life weapon, although it does reload like an RPG, making it the third gun in the game to have a reload animation (the first included in the game, in fact, as the others were added post-release). Shooting a container of napalm, the trail it leaves will light on fire almost instantly, torching anyone and anything in its path - including the player.
One more addition to the game with the Paradise Lost DLC are three instances of a mounted weapon, the M134 Minigun, two of which are accessible by the Dude. The model seems to most closely resemble the USAF's GAU-17/A fitted with the non-slotted flash hider of Dillon Aero's version. Surprisingly, the weapon is actually presented somewhat close to reality - it's mounted rather than man-portable, it's fitted with a sight of some variety, it actually has a visible ammo box mounted on it (despite its typical infinite amount of ammunition), and perhaps most notably it does not overheat no matter how long anyone, the player included, fires it, echoing the primary advantage the six barrels are supposed to give to the weapon. The first one appears on Thursday, mounted in the warehouse of the old postal office, where it is used by the Borderlands-parody boss "Two-Ears", referred to as his "beeg deeck". The next two both show up on Friday, one used by the Survivalists in the forest to, as befitting their status as a S.T.A.L.K.E.R.: Shadow of Chernobyl reference, recreate the infamously-powerful mounted gun protecting the entrance to the game world proper in Clear Sky; this is the sole minigun that cannot be used by the player, or even have the NPC making use of it killed to make it stop firing. The other is in the underground vault below the remains of Habib's store, this one unmanned and technically usable, though given the absurd rush of enemies coming at you is probably not a viable option.