Smith & Wesson Model 63 J Frame Hammer Block .22 LR, Part# 63120
$5.99
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Smith & Wesson Model 63 J Frame Hammer Block .22 LR, Part# 63120
$5.99
Smith & Wesson Model 63 Hammer Block – Part# 63120
This is a genuine factory Smith & Wesson hammer block for the J Frame Model 63 revolver chambered in .22 Long Rifle. An old-style used part in serviceable condition. The hammer block is a critical passive safety component — it prevents the hammer from contacting the firing pin unless the trigger is fully depressed, protecting against accidental discharge from drops or impacts.
If your revolver has a worn, cracked, or missing hammer block, replace it immediately before returning the firearm to service.
Part Details
- Part Number: 63120
- Part Name: Hammer Block
- Condition: Used, factory original (old style)
- Frame: J Frame
- Caliber: .22 Long Rifle (rimfire)
- Function: Passive drop safety — blocks hammer-to-firing-pin contact unless trigger is fully pulled
Model Compatibility
| Model | Caliber | Frame | Compatible |
|---|---|---|---|
| Model 63 | .22 LR (rimfire) | J Frame | ✅ Yes |
| Model 43 / 43C | .22 LR (rimfire) | J Frame | ⚠️ Verify fitment |
| Model 317 | .22 LR (rimfire) | J Frame | ⚠️ Verify fitment |
| Model 34 | .22 LR (rimfire) | J Frame | ⚠️ Verify fitment |
| Model 36 / 60 | .38 Special / .357 Mag | J Frame | ⚠️ Verify fitment — same frame, centerfire |
| K / L / N Frame | Various | Larger frames | ❌ Different frame size |
Note: Hammer blocks are frame-specific and not interchangeable between J, K, L, or N Frame revolvers. Parts may also vary between rimfire and centerfire J Frame configurations and between old-style and current-production revolvers. Always confirm your exact model before ordering. Model numbers are stamped on the frame behind the yoke when the cylinder is swung out. Pre-1957 revolvers may not have a model number — contact us with your serial number for assistance.
Installation
Hammer block replacement requires full disassembly of the lock work. As a critical safety component, we strongly recommend installation by a qualified gunsmith. Do not return the firearm to service without verifying correct function after installation.
Questions about fitment? Call or email us — we're happy to help.