Manhunt

Manhunt is the first game in of Rockstar's more controversial franchises. Manhunt has been banned in several countries and implicated by the British media in a UK murder shortly after it's release [to be exact, implicated by the victim's mother; as it turned out, she was so familiar with the game because it was the victim who owned a copy of Manhunt, not his killer].

Handguns

Smith & Wesson Model 10

The .38 revolver (S&W Model 10) is used by many of the game's characters and is often the handgun of choice for most of the game. Holds 6 rounds and has a surprisingly fast reload rate.

The .38 Revolver

Another view of the .38 revolver

Glock 23

Called a 'Light Handgun' or 'GS Model 23' in the game, the Glock 23 is used in the game by a few gangs (Most notably the "Smileys") and by Lionel Starkweather's (the 'director' who tells you what to do and where to go in the game) personal henchmen. The gun itself is almost a carbon copy of the Glock, with only slight differences in the name and model. For example, the seven slide grooves are now at the front where as the real steel version has them at the back. It is even chambered in .40.

The 'GS Model 23'

The real Glock 23

Desert Eagle

Called the 'Heavy Handgun' or the more decorative 'Avenger Force .50 AE GS' in the game. It is used in the latter stages of the game by Carcer City SWAT and the Cerberus assault team. Like the Glock, the gun is almost an exact replica of the .50 caliber monster. Subtle differences that can be spotted is that the gun, whilst being chambered in .50 Action Express, holds 9 rounds which is what the .357 version of the Desert Eagle holds.

The Desert Eagle in-reality

The Desert Eagle in-game

Shotguns

Sawed Off Shotgun

Powerful up close, the shotgun is used and seen in many areas of the game. Fires two 12 gauge cartridges. Again the make and model are unclear.

The Sawed Off shotgun in the hands of some dangerous people.

More shotgun, more dangerous people.

Franchi SPAS-12

Called a 'Sap 12' or '12-Gauge' in the game. Variants of this gun are carried by the CCPD/SWAT as well as Cerberus with flashlights attached.

The SPAS-12

The SPAS-12 on Cash's back.

Rifles

Enfield L42A1/Enfield Enforcer

Used in only a few missions, the sniper rifle fires 7.62mm ammunition with a six shot capacity. The gun appears to be bolt action and very accurate.

The sniper being aimed by Cash.

Machine Guns

Sub Machine gun

Similar to the Mac-10, the gun has a good range and accuracy, as well as a powerful rate of fire. Carried by CCPD and SWAT in the game, also seen in the hands of what appear to be "The Skinz" as shown in the picture below.

The Mac-10/9mm Uzi lookalike in Manhunt.

if it looks like a MAC and an uzi but in 9mm it could be the Arms Corp. BPX variant of the MAC-10

M16A2

Called the 'Defender Mark 1', the gun can be fired in semi or fully automatic. The gun also features a shortened barrel and high power. 2-3 shots to the body will kill, where as a shot to the head will remove most of it entirely. Also, the gun holds 30 rounds despite being fitted with a 20 round magazine. Only seen in the last few levels of the game in the hands of Cerberus agents.

A Cerberus team member holds an M16.

Miscellaneous Weapons

Nail gun

Only useful at close range. Fires 4 inch nails in quick succession. The only levels in which this weapon is available is "White Trash" and "Fueled by Hate" (Levels 3 and 4 respectively).

Tranquillizer Gun

While technically not a firearm, it is the most nonviolent way to subdue an enemy. It is used in only a few missions. The gun fires .50 caliber Ketamine shots, enough of a dosage to make Mike Tyson fall asleep.