The first handgun in the game is the "Pistol" which is based on the Beretta M9 and uses 9mm Ammo. In a odd design choice, the slide never moves when the pistol is either fired nor reloaded.
.44 Magnum
The only revolver in the game, the .44 Magnum is the strongest handgun the player can find, using the .44 Cartridge. Strangely, the icon for the magnum has a silver color while the actual model is darker. Another odd thing is that the hammer seems to be non-functional, as it's never cocked or moves when the weapon is fired. Fun fact is that the description of the gun references the classic film 'Dirty Harry'.
Sub-Machine Gun
"SMG"
The only sub-machine gun in the game, going by the name SMG, is based on a MP5SD3, though the gun is never fired surpressed nor the "suppressor" hide the weapons flash.
Shotguns
Unknown Shotgun
One of two shotguns in the game, the "Shotgun" is one of the strongest weapons in the entire game, able to deliver devastating damage up close. Like the .44 Magnum, the weapon is colorized in the icon, but the actual model is blackened. NOTE: Both shotgun use the same reload animation.
Unknown Sawed Off Shotgun
The other shotgun you can acquire, it seems to be more or less a sawed-off version of the standard shotgun.
Rifles
"Sniper Rifle"
The "Sniper Rifle" is one of three rifles you can acquire in game. Seemingly based on the Remington R11 RSASS, it's the strongest of both rifles you can get. Surprisingly, unlike the Magnum and Shotguns, both the icon and real-world model are the same color. Again, the weapon is suppressed but it seems to just be there for cosmetic reasons.
"Hunting Rifle"
The "Hunting Rifle", seemingly based on the Karabiner 98k, is the second of the rifles you can get. Oddly, the gun can only fire one round before needing to be reloaded. In another odd design choice, you can't put a scope on it.
Ak 47
The last of the rifles you can craft, the Ak 47 is also the only one to be fully automatic (at the cost of a very poor framerate). Though it seems to be more based on a AKMSU, judging by the icon.