Regina's starting weapon at the beginning of the game, in the game Manual it says the weapon is a "Standard 9mm handgun". It's possible the weapon is actually .357 Magnum, judging by how fast the weapon can be fired as well as the little recoil.
SPAS-12
A Franchi SPAS-12 shotgun is TRAT Special Forces team leader Lieutenant Dylan Morton's weapon of choice.
A Chinese Type 69 RPG is fired at the Tyrannosaur during the base attack by TRAT team member David Fork, distracting it (and destroying its left eye) long enough for Dylan and Regina to avoid becoming the main course.
Two M249 SAWs are seen mounted in fore and aft pintle mounts on the Jeep commandeered by Dylan and Regina when they're attacked by two angry Triceratops.
The M60, known as the Heavy Machine Gun, notice the thumbhole stock
The M60, particularly the M60E3 model appears as the Heavy Machine gun in-game and is a Regina only weapon. It features an odd looking thumb hole stock.
The WA2000 appears mocked up as an Anti-Tank rifle minus a rifle scope and with synthetic furniture instead of wooden stock and fore grip. It is a Dylan only weapon and is suspected to be of .50 Calibre, judging by the size of the spent casings.
The M47 Dragon Anti-Tank Missile, usually used in a stationary position is mocked up as a portable anti-tank rocket launcher. Used by Dylan and David, it's the most powerful weapon in-game.
HK69A1
The HK69A1 is made up as a Flare gun in-game called the Signal Bullet. It is used during the Allosaur Nest and is used by both Dylan and Regina to signal for an artiellry strike.
