Smith & Wesson K Frame Model 66 Cylinder & Yoke Assembly .357 Magnum Stainless - 6678B
$129.99
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Smith & Wesson K Frame Model 66 Cylinder & Yoke Assembly .357 Magnum Stainless - 6678B
$129.99
Smith & Wesson K Frame Model 66 Cylinder & Yoke Assembly – .357 Magnum, Stainless
This factory original Smith & Wesson K Frame Cylinder & Yoke Assembly is a complete stainless steel 6-shot cylinder and yoke unit for the Model 66 Combat Magnum revolver. The non-recessed cylinder design is correct for old-style Model 66 revolvers. The yoke aligns the cylinder with the frame and barrel, while the cylinder houses the six chambers — together they are one of the most critical assemblies in the revolver, directly affecting timing, alignment, and safe operation.
Part Details
- Part Number: 6678B
- Manufacturer: Smith & Wesson
- Frame: K Frame (Medium Frame)
- Model: 66 Combat Magnum
- Caliber: .357 Magnum (also accepts .38 Special)
- Material: Stainless Steel
- Capacity: 6 rounds
- Cylinder Design: Non-Recessed
- Style: Old Style
- Barrel Compatibility: 3" and longer barrels only
- Condition: Used – Factory Original, Good Functional Condition
Model Compatibility
| Model | Caliber | Barrel | Compatible |
|---|---|---|---|
| 66 (old style, 3"+ barrel) | .357 Magnum | 3", 4", 6" | ✓ Yes – Direct Fit |
| 66-1 through 66-4 | .357 Magnum | 3"+ barrel | ✓ Verify – Check non-recessed design |
| 66 (2.5" barrel) | .357 Magnum | 2.5" | ✗ Not Compatible – Different cylinder fit |
| 19 (blued) | .357 Magnum | Various | ✗ Verify – Different finish, same frame |
| 65 (.357 Magnum) | .357 Magnum | Various | ✗ Verify – Different model configuration |
| K Frame .38 Special models | .38 Special | Various | ✗ Not Compatible – Caliber-specific cylinder |
| L, N, J Frame models | Various | Various | ✗ Not Compatible – Frame-specific |
⚠️ Cylinders are caliber-specific and frame-specific. This cylinder fits 3-inch and longer barrels only on old-style K Frame Model 66 revolvers. Verify your exact model, generation, and barrel length before ordering. Professional gunsmith installation and timing verification is required.
Installation Note
Cylinder and yoke replacement requires full timing verification by a qualified gunsmith. Improper installation can result in dangerous cylinder misalignment. Do not attempt installation without proper tools and gunsmithing knowledge.