Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B

Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used OEM 66120

$6.99
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Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
  • Smith & Wesson Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used - 66120B Part 66120B
Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used OEM 66120

Smith & Wesson K Frame Model 66 Hammer Block Old Style .357 Magnum Used OEM 66120

$6.99

This listing is for the Smith & Wesson K Frame Model 66 Hammer Block, Old Style (Used OEM Part 66120) only.

Genuine Smith & Wesson OEM hammer block for the K Frame Model 66 Combat Magnum revolver chambered in .357 Magnum. The hammer block is a critical passive safety component that physically prevents the hammer from contacting the firing pin unless the trigger is fully depressed — a worn or non-functional hammer block is a serious safety concern. This is the old style hammer block, fitting Model 66 through 66-3. Old and new style hammer blocks are not interchangeable — verify your dash number before ordering.

Part Details

  • Part Number: 66120
  • Condition: Used — inspected and functional
  • Manufacturer: Smith & Wesson
  • Part Type: Hammer Block
  • Style: Old Style (Pre-MIM)
  • Frame: K Frame
  • Caliber: .357 Magnum

Model Compatibility

Make Model Dash Caliber Compatible
Smith & Wesson Model 66 66, 66-1, 66-2, 66-3 .357 Magnum ✓ Yes — Old Style
Smith & Wesson Model 66 66-4 and later (MIM) .357 Magnum ✗ No — requires new style
Smith & Wesson Other K Frame models Various Various Verify before ordering

The 66-4 introduced a new style hammer block design not interchangeable with this part. To find your dash number, swing out the cylinder and look behind the yoke on the frame.

Installation Note

Gunsmith Recommended: The hammer block is a safety-critical component. Some fitting may be required. Always function test after installation to confirm proper hammer block engagement before carrying or firing.

We only ship to addresses within the United States.

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