There are eleven useable weapons in L.A. Noire. You are automatically given a service gun with unlimited ammo. Other weapons can be found during a gun battle or in the trunks of police cars during raids and other skirmishes.
Colt 45
Your service weapon. It has unlimited ammo.
Colt 38
Only available in “Armed and Dangerous”. You must drop your shotgun to use it.
Ithaca Full Stock Shotgun
Given to you automatically during “Armed and Dangerous”. This shotgun is available (alongside the drummed Thompson) in police vehicle trunks that carry weapons.
M1 Garand Rifle
This .30 caliber rifle was standard issue for the US Armed Forces from 1936 to 1957. You can get the M1 Garand from fallen enemies. The enemy at the end of Fallen Idol carries one.
M1 Thompson
A more common weapon that can be found during several cases, including Street Crime missions.
Nickel Plated Pistol
Replaces Cole Phelps’ default handgun when wearing The Sharpshooter outfit. Identical to the default handgun, except it is nickel plated.
CHICAGO PIANO
You can find the Chicago Piano in the trunk of any police vehicle that yields weapons. This weapon is used by Mickey Cohen’s gangsters and Leland Monroe’s gunmen and thus can be collected from their bodies.
Browning Automatic Rifle
Claim the BAR in “Manifest Destiny”, “A Polite Invitation”, and “A Different Kind of War”. This powerful, long-range, assault rifle packs an enormous punch per round.
FN Browning
Jack Kelso’s default pistol; used in “A Polite Invitation”. It’s his default weapon, so it has unlimited ammo.
Flamethrower
Find this in a weapons cache in the sewer tunnels during “A Different Kind Of War”.