Weapons - Dead Space 2 wiki

Plasma Cutter:

The default weapon of the game.

Alt Fire: Changes the orientation between vertical and horizontal

Special: Sets Enemies on fire.

Max damage: 18 Pts.

Nodes required to max damage + special: 12 nodes

Javelin Gun:

Weapon available in the first store.

Alt Fire: Delivers a shock to all enemies near the spear after it has been fired.

Ammo Schematic: in the Unitology plaza, at the end of chapter 3.

Special: Spears explode like grenades after shocking with the alt fire.

Max damage: 100 Pts.

Max Alt. Fire damage: 16 Pts.

Nodes required to max damage and Alt. D  

Line Gun:

Weapon available in the first store.

Alt Fire: Places a timed mine.

Ammo Schematic: in the Unitology storage area, the middle of chapter 5.

Pulse Rifle:

Weapon Schematic: at the start of chapter 3.

Ammo Schematic: in the middle of chapter 6.

Alt Fire: Grenade Launcher

Max damage: 9 Pts.

Max Alt. Fire damage: 9 Pts.

Nodes required to max damage: 13 nodes

Nodes required to max Alt. Fire damage:  6 nodes off of main branch (10 nodes total)

Ripper:

Weapon Schematic: in the gravity shunt room in chapter 5.

Ammo Schematic: at the bottom of the maintenance pod shaft in chapter 7.

Alt Fire: Ranged Shot

Max Damage: 16 Pts.

Max Damage Alt. Fire: 30 Pts.

Nodes required to max damage: 12 nodes

Nodes required to max Alt. Fire: 7 nodes

Detonator:

Weapon Schematic: in the save room at the church executive's office (before meeting Daina) in chapter 5.

Ammo Schematic: in the processing plant room with the workbench in chapter 8.

Alt Fire: Disarms the mine to be picked up.

Special Fire: Extended blast radius

Seeker Rifle:

Weapon Schematic: in the start of chapter 6, the balcony "room" where the laundromat is.

Ammo Schematic: in the Stalker cargo room (past the Guardian), after Isaac leaves the tram to check the track in chapter 9.

Alt Fire: Toggles Zoom

Max damage: 70 Pts.

Max damage Alt. Fire: 100 Pts.

Nodes required to max damage: 11 nodes

Nodes required to max Alt. Fire damage: 10 nodes

Flamethrower:

Weapon Schematic: in the last classroom before the school playground in chapter 6.

Ammo Schematic: in chapter 9, where Ellie's old crew barricaded themselves on a balcony of the fuel tower. Look for laser tripmines that indictate their position.

Max damage: 12 Pts.

Max Alt. Fire damage: 2.2 Pts.

Nodes required to max damage: 15 nodes

Nodes required to max Alt. Fire damage: 6 nodes

Force Gun:

Weapon Schematic: in a locker at the top of the maintenance pod ride in chapter 7.

Ammo Schematic: in the ship's centrifuge chamber in chapter 10. Get it before activating the machinery, since you need to be in zero-G.

Contact Beam:

Weapon Schematic: in the node-locked room of chapter 7 (before going outside to align the solar arrays).

Ammo Schematic: in the zero-G zone of chapter 11. Check the exit tunnel's exterior; the plan is floating in space where the tunnel connects to the rock.

Alt Fire: Sends a blast radius out knocking over and damaging enemies.

Special: Adds stasis to the alt fire.

Max Alt. Fire damage: 5 Pts.