The current weapons on board the USS Sanctuary are wide and varied. Standard weapons include one energy sidearm usually a laser and a long arm issued based on circumstances as required. There are also weapons modifications that can also add accuracy or stability to the weapon. Also specific models of weapons might have diffrent added bonuses but a 9mm is still a 9mm at the end of the day.
Ammunition is HEAVY so you have to be careful with how much you carry. As a general rule all pistol magazines have a .5 lb. weight full. All Assault rifles and SMGs magazines have a weight of 1 lb. All belts fully loaded weight 10lbs. Energy cells for pistols weight 1 lb. and energy cells for all other weapons weight 3lbs. See the individual explosives for their weight.
Basic information on energy weapons:
Personal Lasers: Super accurate long range weapons. This was the first energy weapon deployed by the USNC. As of now it comes in many power levels and configurations from combat rifle to sniper rifle. UNSC was even field testing an energy shotgun like weapon designed for battle field suppression.
Personal Plasma: Less accurate but more powerful. This is a super-heated ion plasma weapon that can burn through almost any material given enough time. Some Marines prefer this weapon as it packs more stopping power. However this weapon is not recommended on ship boarding actions as they can punch holes in the hull of smaller vessels with ease.
Personal Ionizing: Not issued to UNSC personnel as these weapons only damage shields and irradiate personnel. Considered an inhumane weapon of mass destruction and was banned by the UNSC. Considered and excellent boarding weapon as it does not typically damage systems or materials but kills hostile crewmen.
Basic information on High Velocity Weapons (HV):
Infantry Gauss weapons: Electromagnetic slug throwers capable of tossing metal at hyper sonic speeds. These weapons can penetrate all shields and any armor not specially designed to stop them. They also can punch holes in the sides of ships if the hull is thin enough but this is less likely then when using plasma weapons.
Infantry Ramjet rounds: More like regular bullets but made from a titanium alloy filled with a ceaseless jet fuel. Once fired the jet fuel in the nose ignites making a hypersonic round. Same danger of penetrating the hull exists when using these same as the gauss rifle. These weapons were the standard issue HV weapon for years before Gauss technology and are only used now in energy damping environments where gauss and energy weapons are useless.
Basic information Ballistic Weapons:
Used for hundreds of years on earth and the colonies these are the standard civilian weapons allowed in the fleet and on the surface of planets. While no match for modern body armor they are useful in boarding actions if they have the right ammunition and have almost zero chance of piercing the hull. These are issued to ships guards and civilian police. They have a huge verity of calibers and models but the ammunition is easy to manufacture.
Basic Information about Melee weapons:
Although not often used but still taught, knives, swords, and asps are still issued to soldiers and civilian forces alike. Shields and most body armor is not designed to stop such weapons and there have been many documented cases that close action ship boarding has come down to knives and asps.
Heavy Weapons: These can be both energy and slug throwers but they all have one thing in common. They are heavy fire lots of rounds at once or fire something that goes BOOM! or in horrifying cases BOTH. Any one using these weapons should be very aware that they are dangerous in close quarters and in unskilled hands can be as letal to the friendlies as to the enemy.
Explosives: These are thrown, set, hidden, command detonated, trip wired, and radioed, but they all do the same thing. Splode. Some big some small but at the end of the day they splode.