Resident Evil 4

Handgun (H&K USP)

Leon Kennedy's standard weapon

Punisher (FN Five-seveN)

Based off of Fabrique Nationale's Five-seveN handgun which normally chambers the 5.7mm cartridge originally intended to pierce low-levels of body armor. The version seen in-game chambers regular 9mm Parabellum.

This weapon can be purchased from the Merchant, or won in a contest after shooting ten of sixteen blue targets scattered across two areas. If all targets have been shot, the Punisher will have a free upgrade added onto it, making it slightly more powerful than an unupgraded Handgun.

Red 9 (Mauser C96)

A 9mm version of the Mauser C96 handgun, one of the first automatic handguns to enter production in the world. The Red9 version was developed during World War I and chambered 9mm Parabellum to keep ammo supplies standard, but when soldiers began to load the weapon with the wrong type of ammunition, a large Red 9 was placed on the grip to differentiate the model from the standard Mauser.

This weapon can be purchased from the Merchant, along with a stock which improves its accuracy significantly.

Blacktail (Springfield Armory XD-9)

Purchased from the Merchant.

Matilda (HK VP-70)

Unlocked to be purchased from the Merchant after successfully completing the Normal difficulty of the game.

Shotgun (Remington 870)

May be obtained in one of three ways. On Easy mode the weapon is in your inventory, on Normal modes or higher you may obtain it for free in the upstairs section of a house in the Ganados Village, or you may purchase this weapon from the Merchant.

Riot Shotgun (Benelli M4 Super 90)

May be purchased from the Merchant.

Striker (DAO-12 "Street Sweeper")

May be purchased from the Merchant.

Bolt Action Rifle (Springfield M1903A4)

Brought off merchant

Semi-Auto Rifle (H&K SL8)

brought off merchant

TMP (Steyr TMP)

brought off merchant

Chicago Typewriter (Thompson M1A1)

is brought off merchant

Broken Butterfly (Schofield Model 3)

Found in castle or brought off merchant

Killer 7 (AMT Hardballer)

brought off merchant

Handcannon (S&W Model 500)

Get a five-star rank with all characters on all stages. (Mercenary Mode)

Minethrower

Brought off merchant

Rocket Launcher/Special Rocket Launcher/Infinite Launcher (RPG-7)

the usaul rocket launcher can be found in the castle or brought off merchant. The special rocket launcher is given to you by ada wong the infinate one is unlocked by beating normal mode

Los Illuminados Gatling Gun

as far as i can tell only one boss uses this weapon