Smith & Wesson K Frame Model 66 .357 Magnum Hammer .375" Spur Key Lock (MIM) Used, Part# 66107E

Smith & Wesson K Frame Model 66 Hammer — Part# 66107E

OEM Smith & Wesson replacement hammer for the Model 66 Combat Magnum revolver. This is a used, original-style MIM (Metal Injection Molded) hammer with a .375" spur, designed for Key Lock (internal lock) equipped revolvers.

Part Details

• Part Number: 66107E
• Spur Width: .375"
• Construction: MIM (Metal Injection Molded)
• Style: Old Style / Original Configuration
• Condition: Used — functional, shows normal wear
• Lock Type: Key Lock (Internal Lock) compatible

Compatible Models

This hammer is compatible with Smith & Wesson K Frame centerfire revolvers equipped with the internal key lock, including:

• Model 66 (.357 Magnum) — primary fit
• Model 65 (.357 Magnum) — verify key lock configuration
• Model 13 (.357 Magnum) — verify key lock configuration
• Other K Frame centerfire models with key lock and matching hammer channel — verify before ordering

Note: Not compatible with rimfire K Frame models (17, 18, 48, 617, 648). Rimfire hammers use a different firing pin configuration and are not interchangeable with centerfire hammers.

Installation

Gunsmith installation recommended. Proper fitting and timing verification required after hammer replacement on any S&W revolver.