Weapons | Mass Effect 3 Wiki

Weapon System

In Mass Effect 3, systems from both Mass Effect and Mass Effect 2 are meshed together. Like in the original game, there is a large amount of Weapons at your disposal as well as the return of Weapon Mods, that are used to strengthen different areas of a Weapon. 

Weapons can be selected and modified at the beginning of Missions, although there are some occasional opportunities to change loadouts during specific points of certain Missions. When a new Weapon is found during a Mission, it provides the opportunity to change Weapons for Commander Shepard and the whole squad right there. This is limited to weapon types, you can't change weapon mods.

Weapon Upgrades

Weapon levels return from the original Mass Effect, but they no longer depend on random drops or player level as they did on the first game, but are upgraded now. Upgrading a weapon increases its reserve Ammo Capacity, Damage and Accuracy while reducing its weight.

Upgrades can be done at a terminal located in the Shuttle Bay at a cost in credits. On your first playthrough, your Weapons can't be upgraded beyond level V. If you create a New Game Plus using that first playthrough, it will carry over the upgrade level and will allow you to reach level X.

If you want information on Weapon Mods, click the link.

Assault Rifles

These Weapons provide a good balance between stopping power and accuracy. Can be commonly seen as the preferred Weapon by Mercenaries or Companions alike.

Heavy Pistols

These handguns are all-purpose weapons that are effective even at long range. They are the most accurate and powerful Weapons outside of Sniper Rifles. Heavy pistols' clips are small, though, and need to be reloaded often.

Heavy Weapons

Heavy Weapons deal massive damage to Enemies and Bosses, but ammo is limited and can only be picked from the battlefield. Once the ammo clip is depleted, it will be automatically thrown by Commander Shepard.

Shotguns

Shotguns are brute force Weapons that deal massive damage at close range. Even though they have a slow rate of fire, if you are close enough to the target, there won't be need to pull the trigger again. 

Sniper Rifles

Sniper rifles are extremely lethal from distance, and can help you take out Enemies from afar without being detected with deadly precision. Their most noticeable drawbacks are their slow rate of fire and maneuverability for close to mid-range combat.

Submachine Guns

Submachine Guns are ideal for close to mid-range combat, with a good amount of ammunition at their disposal and high rate of fire. The generally low accuracy and damage per shot are their only flaws