Smith & Wesson Model 51 J Frame Bolt, Spring & Plunger .22 Magnum, Part# 5145
$19.99
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Smith & Wesson Model 51 J Frame Bolt, Spring & Plunger .22 Magnum, Part# 5145
$19.99
Smith & Wesson Model 51 Bolt, Spring & Plunger – Part# 5145
This is a genuine factory Smith & Wesson bolt, spring, and plunger set for the J Frame Model 51 revolver chambered in .22 Magnum Rimfire (.22 WMR). An old-style used part in serviceable condition — a cost-effective solution for restoring proper cylinder lockup on your Model 51.
In S&W revolver terminology, the bolt (also called the cylinder stop) rises to lock the cylinder in precise alignment with the barrel at the moment of firing. The plunger is the pin that drives the bolt upward into the cylinder notch, and the spring provides the tension to keep it engaged. A worn, chipped, or broken bolt, fatigued spring, or damaged plunger results in cylinder wobble, poor lockup, and degraded accuracy or reliability.
Part Details
- Part Number: 5145
- Part Name: Bolt, Spring & Plunger (Cylinder Stop Assembly)
- Condition: Used, factory original (old style)
- Frame: J Frame
- Caliber: .22 Magnum Rimfire (.22 WMR / .22 M.R.F.)
- Includes: Bolt (cylinder stop) + spring + plunger
- Function: Locks cylinder in barrel alignment at moment of firing
Model Compatibility
| Model | Caliber | Frame | Compatible |
|---|---|---|---|
| Model 51 | .22 Magnum (.22 WMR) | J Frame | ✅ Yes |
| Model 53 | .22 Jet / .22 LR | J Frame | ⚠️ Verify fitment |
| Model 63 | .22 LR (rimfire) | J Frame | ⚠️ Verify fitment — different rimfire caliber |
| Model 34 | .22 LR (rimfire) | J Frame | ⚠️ Verify fitment — different rimfire caliber |
| Model 36 / 60 | .38 Special / .357 Mag | J Frame | ⚠️ Verify fitment — centerfire |
| K / L / N Frame | Various | Larger frames | ❌ Different frame size |
Note: The Model 51 is chambered in .22 Magnum Rimfire (.22 WMR) — not .22 LR. Bolt assemblies are frame-specific and not interchangeable between J, K, L, or N Frame revolvers. Parts may also vary between rimfire caliber configurations (.22 WMR vs .22 LR) 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.
Installation
Bolt, spring, and plunger replacement requires side plate removal and disassembly of the lock work. Cylinder timing must be verified after installation to ensure safe, reliable lockup. We recommend installation by a qualified gunsmith.
Questions about fitment? Call or email us — we're happy to help.