{"product_id":"cmmg-barrel-bolt-group-kit-4-5-22-lr-4140-chrome-moly-1-16-twist-ar-15-conversion","title":"CMMG Barrel \u0026 Bolt Group Kit 4.5\" .22 LR 4140 Chrome Moly 1:16 Twist - AR-15 Conversion","description":"\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eConvert your existing \u003cstrong\u003eAR-15\u003c\/strong\u003e upper into a dedicated \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003e.22 LR\u003c\/span\u003e\u003c\/strong\u003e rimfire platform with the \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003eCMMG Barrel \u0026amp; Bolt Group Kit\u003c\/span\u003e\u003c\/strong\u003e. This matched \u003cstrong\u003e4.5\" medium taper\u003c\/strong\u003e barrel and rimfire bolt group is purpose-built for cost-effective rimfire training, plinking, and small-game hunting on your existing MSR upper without the cost and noise of a 5.56 round.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe barrel is precision-machined from \u003cstrong\u003e4140 Chrome Moly steel\u003c\/strong\u003e and finished with a \u003cstrong\u003esalt bath nitride\u003c\/strong\u003e treatment inside and out for excellent corrosion resistance, lubricity, and easy cleanup. It carries a \u003cstrong\u003e1:16 twist rate\u003c\/strong\u003e optimized for high-velocity and bulk \u003cstrong\u003e.22 LR\u003c\/strong\u003e ammunition, a \u003cstrong\u003e.22 LR sporting chamber\u003c\/strong\u003e for reliable cycling, and a \u003cstrong\u003e1\/2x28 thread pitch\u003c\/strong\u003e that accepts any standard AR-15 muzzle device or suppressor.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe included rimfire bolt group is engineered specifically for \u003cstrong\u003e.22 LR\u003c\/strong\u003e function, dropping into a compatible CMMG Mk4 \/ AR-15 upper in place of the standard 5.56 bolt. This kit is the heart of any CMMG \u003cstrong\u003e.22 LR conversion\u003c\/strong\u003e, giving you a quiet, low-recoil rimfire option on a familiar platform. \u003cstrong\u003eBarrel and bolt only\u003c\/strong\u003e - upper receiver, handguard, and other components sold separately.\u003c\/span\u003e\u003c\/p\u003e","brand":"CMMG","offers":[{"title":"Default Title","offer_id":55292582428994,"sku":"22D5B6E","price":266.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0997\/7921\/5682\/files\/alt_35f7e4e7-f943-4532-9b61-22b0cf09a830.jpg?v=1785103093","url":"https:\/\/centerfiresystems.com\/products\/cmmg-barrel-bolt-group-kit-4-5-22-lr-4140-chrome-moly-1-16-twist-ar-15-conversion","provider":"Centerfire Systems","version":"1.0","type":"link"}