As in previous Metal Gear games, all equipment is procure-on-sight, meaning that you must find your weapons in the field, but ammo acquisition has changed in this installment. You no longer have to find certain types of bullets for one weapon, for example, 5.56mm rounds will work for any weapon that fires 5.56mm rounds. You can also buy weapons and ammo from Drebin's Shop, but you can find almost every weapon Drebin has for sale in the field, so save your Points for Custom Parts and Ammunition. Also, if you kill or knock out a PMC Soldier and pick up his weapon and it is ID Locked, you will not be able to use it until you launder it to Drebin, so keep that in mind!
Customizing
An interesting feature in MGS4 is the ability to Customize your weapons however you like. But, be sure the parts you want to buy are the parts you are actually going to use. For example, you don't need to buy a Silencer for your weapon if you are planning on using it to kill the enemy when they have spotted you, you don't need to buy a Laser Sight for your weapon if the weapon is a Sniper Rifle. Certain attachments onto your weapons are not necessary, such as the Flashlight (you have the Solid Eye, which has night vision). The point is, spend your Drebin Points wisely.
Acquisition
You can acquire many weapons and custom parts in the field, even those sold by Drebin. Here's a list of where to find these weapons.
Middle East
Note: The weapons listed here are those found without ID Locks found in the Middle Eastern chapter.
Weapon: Stun Knife
Category: Melee
Location: Equipped at beginning of Middle Eastern Chapter
Weapon: AK-102
Category: Assault Rifle
Location: Found near pile of crates at beginning of Middle Eastern Chapter
Weapon: Petrol Bomb
Category: Incendiary/Thrown
Location: Sometimes dropped by Militiamen during body shakedown
Weapon: Operator
Category: Handgun
Location: Given to Snake by MK. II
Weapon: Mk. I
Category: Tranq. Gun
Location: Given to Snake by MK. II
Weapon: M4
Category: Assault Rifle
Location: Given to Snake by Drebin
Weapon: RPG-7
Category: Rocket Launcher
Location: Found near entrance to Militia Safehouse
Weapon: HK21E
Category: Machine Gun
Location: Near the Militia Safehouse exit, two Militiamen will be talking about gun laundering, one of them is holding this weapon. Use the Solid Eye to identify him, and use your Tranq. Gun to knock him out when they walk away to obtain the weapon.
Weapon: Sleep Gas Mine
Category: Mine
Location: Advent Palace, either crawl over the mine to obtain it or use the MK.II to disarm and obtain it
Weapon: Sleep Gas Satchel
Category: Remote Mine
Location: Advent Palace, behind the bar
Weapon: Claymore
Category: Mine
Location: Advent Palace, either crawl over the mine to obtain it or use the MK.II to disarm and obtain it
Note: The following weapons are those found with ID Locks in the Middle Eastern chapter, and is not a complete list as of yet.
Weapon: Mk. 17
Category: Assault Rifle
Location: Carried by almost all PMC Soldiers
Weapon: M14EBR
Category: Sniper Rifle
Location: Inside a building housing multiple PMC Snipers in Urban Ruins area
Weapon: P90
Category: Sub-Machine Gun
Location: Carried by FROG Soldiers during their attack on the Advent Palace
Weapon: Javelin
Category: Anti-Tank Missile Launcher
Location: Found on a rooftop after you exit the Advent Palace parking garage and get onto the street where the Militia tank is fighting the PMC Soldiers
Weapon: Frag Grenade
Category: Explosive/Thrown
Location: Sometimes dropped by PMC Soldiers during body shakedown
Weapon: White Phosphorus Grenade
Category: Incendiary/Thrown
Location: Inside a room with two dead PMC Soldiers in Militia Safehouse
Weapon: Stun Grenade
Category: Non-Lethal/Thrown
Location: Sometimes dropped by PMC Soldiers during body shakedowns
Weapon: Smoke Grenade
Category: Non-Lethal/Thrown
Location: Sometimes dropped by PMC Soldiers during body shakedowns
Weapon: GSR
Category: Handgun
Location: Inside a room with two dead PMC Soldiers in Militia Safehouse
Custom Parts
Note: This is a list of custom parts found in the Middle Eastern Chapter, and it is not a complete list as of yet.
Part: Red Dot Sight
Location: Beginning of Urban Ruins area, at the top of a staircase near some boxes
Part: M4 Silencer
Location: Locker in the building near Liquid's camp
Part: Handgun Flashlight
Location: Urban Ruins area, behind a collapsed staircase
South America
Note: This is a list of weapons found in South America without ID Locks, and is not a complete list as of yet.
Weapon: G3A3
Category: Assault Rifle
Location: Carried by almost all Rebel Guerrilla Fighters
Weapon: SVD
Category: Sniper Rifle
Location: Found in a barn at beginning of South America Chapter
Weapon: Twin Barrel
Category: Shotgun
Location: If you take out the two PMC Soldiers standing watch over the Rebels at the beginning of the South America Chapter, they will get up and unlock the door of a building they are using as an armory, and you will find it on the floor
Weapon: G186
Category: Handgun
Location: Carried by a small number of Rebels in Vista Mansion area
Weapon: PKM
Category: Machine Gun
Location: Carried by Rebels in Power Station and Vista Mansion areas
Weapon: C4
Category: Remote Explosive
Location: Found in Power Station are
Weapon: M10
Category: Sub-Machine Gun
Location: Carried by a single Rebel in beginning of South America Chapter
Weapon: PSS
Category: Handgun
Location Fireplace of the mansion in Vista Mansion area
Custom Parts
Note: This is a list of all custom weapon parts found in South America, and is not a complete list as of yet.
Part: Weapon Scope
Location: Found in Power Station area by climbing the ladder on the tower that you can reach and hanging off the wire, and dropping down off the wire onto the other tower
Part: Masterkey(Shotgun Attachment)
Location: Carried by certain PMC Soldiers in Vista Mansion area, either kill them or knock them out to get the part
Part: XM203(Grenade Launcher Attachment)
Location: Carried by certain PMC Soldiers in Vista Mansion area, either kill them or knock them out to get the part
Tips
Well, now that you know the basics, here are a few tips to help you with weapons in the game.
- Make sure you can hit your target: Don't just fire blindly a the target, get a bead on it, then fire!
- Know your weapons: Make sure you know how your weapons fire and how to use them to the best of their abilities.
- Grenades are your friend: Throw grenades to get enemies out from behind cover and to take out large clusters of enemies without wasting ammo.