Primary Weapons in Modern Warfare 3 range from Assault rifles and snipers to shotguns. Players can even grab a Riot Shield for some bullet-resistant protection.
Assault Rifles

M4A1
Fully automatic, all purpose weapon.
Unlocked: Default

M16A4
3 round burst.
Unlocked: Default

Scar-L
Fully automatic, all purpose weapon.
Unlocked: Level 6

CM901
Fully automatic, all purpose weapon.
Unlocked: Level 18

Type 95
3 round burst.
Unlocked: Level 32

G36C
Full automatic, all purpose weapon.
Unlocked: Level 42

ACR 6.8
Fully automatic, all purpose weapon.
Unlocked: Level 50

MK14
Semi-automatic (single fire).
Unlocked: Level 60

AK-47
Fully automatic, all purpose weapon.
Unlocked: Level 68

FAD
Fully automatic, all purpose weapon.
Unlocked: Level 78
Submachine Guns

MP5
Fully automatic, close range.
Unlocked: Default

UMP45
Fully automatic, close range.
Unlocked: Default

PP90M1
Fully automatic, high fire rate.
Unlocked: Level 28

P90
Fully automatic, large magazines.
Unlocked: Level 38

PM-9
Fully automatic, close range.
Unlocked: Level 56

MP7
Fully automatic, close range.
Unlocked: Level 74
Light Machine Guns

L86 LSW
Fully automatic, large magazines.
Unlocked: Default

MG36
Fully automatic, large magazines.
Unlocked: Default

PKP Pecheneg
Fully automatic, large magazines.
Unlocked: Level 14

MK46
Fully automatic, large magazines.
Unlocked: Level 54

M60E4
Fully automatic, large magazines.
Unlocked: Level 72
Sniper Rifles

Barrett .50CAL
Semi-automatic (single fire).
Unlocked: Default

L118A
Bolt action.
Unlocked: Default

Dragunov
Semi-automatic (single fire).
Unlocked: Level 12

AS50
Semi-automatic (single fire).
Unlocked: Level 22

RSASS
Semi-automatic (single fire).
Unlocked: Level 44

MSR
Bolt Action.
Unlocked: Level 66
Shotguns

USAS 12
Fully automatic.
Unlocked: Default

KSG 12
Pump action.
Unlocked: Default

SPAS 12
Pump action.
Unlocked: Level 26

AA-12
Fully automatic, low ammo.
Unlocked: Level 26

Striker
Semi-automatic (single fire).
Unlocked: Level 48

Model 1887
Lever-action.
Unlocked: Level 62
Melee

Riot Shield
Bullet Resistant.
Unlocked: Default