{"product_id":"smith-wesson-model-51-j-frame-bolt-spring-plunger-22-magnum-5145","title":"Smith \u0026 Wesson Model 51 J Frame Bolt, Spring \u0026 Plunger .22 Magnum, Part# 5145","description":"\u003ch2\u003eSmith \u0026amp; Wesson Model 51 Bolt, Spring \u0026amp; Plunger – Part# 5145\u003c\/h2\u003e\u003cp\u003eThis is a genuine factory Smith \u0026amp; 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.\u003c\/p\u003e\u003cp\u003eIn S\u0026amp;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.\u003c\/p\u003e\u003ch3\u003ePart Details\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 5145\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Name:\u003c\/strong\u003e Bolt, Spring \u0026amp; Plunger (Cylinder Stop Assembly)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e Used, factory original (old style)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrame:\u003c\/strong\u003e J Frame\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCaliber:\u003c\/strong\u003e .22 Magnum Rimfire (.22 WMR \/ .22 M.R.F.)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e Bolt (cylinder stop) + spring + plunger\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunction:\u003c\/strong\u003e Locks cylinder in barrel alignment at moment of firing\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eModel Compatibility\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eCaliber\u003c\/th\u003e\n\u003cth\u003eFrame\u003c\/th\u003e\n\u003cth\u003eCompatible\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 51\u003c\/td\u003e\n\u003ctd\u003e.22 Magnum (.22 WMR)\u003c\/td\u003e\n\u003ctd\u003eJ Frame\u003c\/td\u003e\n\u003ctd\u003e✅ Yes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 53\u003c\/td\u003e\n\u003ctd\u003e.22 Jet \/ .22 LR\u003c\/td\u003e\n\u003ctd\u003eJ Frame\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 63\u003c\/td\u003e\n\u003ctd\u003e.22 LR (rimfire)\u003c\/td\u003e\n\u003ctd\u003eJ Frame\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment — different rimfire caliber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 34\u003c\/td\u003e\n\u003ctd\u003e.22 LR (rimfire)\u003c\/td\u003e\n\u003ctd\u003eJ Frame\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment — different rimfire caliber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel 36 \/ 60\u003c\/td\u003e\n\u003ctd\u003e.38 Special \/ .357 Mag\u003c\/td\u003e\n\u003ctd\u003eJ Frame\u003c\/td\u003e\n\u003ctd\u003e⚠️ Verify fitment — centerfire\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK \/ L \/ N Frame\u003c\/td\u003e\n\u003ctd\u003eVarious\u003c\/td\u003e\n\u003ctd\u003eLarger frames\u003c\/td\u003e\n\u003ctd\u003e❌ Different frame size\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cem\u003eNote: 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.\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eInstallation\u003c\/h3\u003e\u003cp\u003eBolt, 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.\u003c\/p\u003e\u003cp\u003eQuestions about fitment? Call or email us — we're happy to help.\u003c\/p\u003e","brand":"Smith \u0026 Wesson","offers":[{"title":"Default Title","offer_id":40821860270138,"sku":"5145","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1423\/2020\/files\/DSC06742.jpg?v=1741965893","url":"https:\/\/usagunsandgear.com\/products\/smith-wesson-model-51-j-frame-bolt-spring-plunger-22-magnum-5145","provider":"USA Guns And Gear","version":"1.0","type":"link"}