Halo 3 weapons

Halo 3 features a wide variety of weapons featuring machine guns, pistols, plasma guns, swords & giant hammers, and explosives. These are the confirmed weapons known to be in the Halo 3(all are subject to change):

Covenant Loyalists

 * Plasma Pistol (Dual Wieldable)
 * Plasma Rifle (Dual Wieldable)
 * Needler
 * Covenant Carbine
 * Particle Beam Rifle
 * Energy Sword
 * Fuel Rod Cannon
 * Plasma Cannon
 * Plasma Grenade
 * Type-25 "Spiker" Carbine (Dual Wieldable)
 * Mauler (Dual Wieldable)
 * Brute Shot
 * Gravity Hammer
 * Type-2 "Spike" Antipersonnel Fragmentation Grenade
 * Type-3 "Firebomb" Antipersonnel/Antimateriel Incendiary Grenade

Covenant Separatist

 * Plasma Pistol (Dual Wieldable)
 * Plasma Rifle (Dual Wieldable)
 * Needler
 * Covenant Carbine
 * Particle Beam Rifle
 * Energy Sword
 * Fuel Rod Cannon
 * Plasma Cannon
 * Plasma Grenade

UNSC

 * M6G Magnum Sidearm (Dual Wieldable)
 * M7/Caseless Sub-Machine Gun (Dual Wieldable)
 * MA5C ICWS Assault Rifle
 * BR55HB SR Battle Rifle
 * M90 Shotgun
 * SRS99D-S2 AM Sniper Rifle
 * M41 SSR MAV/AW Rocket Launcher
 * W/AV Model 6 Grindell/Galileian Nonlinear Rifle
 * Missile Pod
 * M7057 Defoliant Projector
 * AIE-486H Heavy Machine Gun
 * M9 HE-DP Fragmentation Grenade

Forerunner

 * Sentinel Beam

Other

 * Fusion Core - As revealed in a Weekly Update, they will be redesigned and may include an as of yet unnamed feature. Also may be equipment.