{"product_id":"luth-ar-ftbl-b24m-24-fluted-bull-barrel-223-rem-5-56-nato-complete-upper","title":"Luth-AR FTBL-B24M 24\" Fluted Bull Barrel 223 Rem \/ 5.56 NATO Complete Upper","description":"\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003eLuth-AR FTBL-B24M\u003c\/span\u003e\u003c\/strong\u003e complete upper assembly is built around a 24-inch \u003cstrong\u003efluted bull barrel\u003c\/strong\u003e chambered in \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003e223 Remington \/ 5.56 NATO\u003c\/span\u003e\u003c\/strong\u003e, and ships ready to drop onto any mil-spec AR-15 lower receiver.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe barrel is machined from \u003cstrong\u003e416 stainless steel\u003c\/strong\u003e with a \u003cstrong\u003e1:9\u003c\/strong\u003e twist and 5R rifling for improved accuracy and easier cleaning. An \u003cstrong\u003eM4 feed ramp\u003c\/strong\u003e supports reliable feeding, while the fluted profile trims overall weight and helps the barrel shed heat during extended strings of fire. The barrel mates to an \u003cstrong\u003eA3 flattop\u003c\/strong\u003e upper receiver that accepts any standard AR-15 picatinny-mounted optic or rear sight, and the assembly is compatible with a \u003cstrong\u003erifle-length gas system\u003c\/strong\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eInside, the upper is completed with an \u003cstrong\u003e8620 steel\u003c\/strong\u003e bolt carrier, a \u003cstrong\u003e4130 alloy\u003c\/strong\u003e carrier key, and a \u003cstrong\u003e4340 chromoly\u003c\/strong\u003e cam pin, all finished to military heat-treat specifications for long service life. A \u003cstrong\u003e15\" KeyMod\u003c\/strong\u003e handguard fits around the bull barrel profile and provides generous rail real estate for lights, lasers, bipods, and forward grips.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe FTBL-B24M is a turnkey solution for builders assembling a long-range, varmint, or DMR-style AR-15 platform.\u003c\/span\u003e\u003c\/p\u003e","brand":"Luth-AR","offers":[{"title":"Default Title","offer_id":55082490102082,"sku":"196429","price":541.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0997\/7921\/5682\/files\/hires_5c9f5e20-08fc-460a-b0ad-252b3fd0fe02.png?v=1784766042","url":"https:\/\/centerfiresystems.com\/products\/luth-ar-ftbl-b24m-24-fluted-bull-barrel-223-rem-5-56-nato-complete-upper","provider":"Centerfire Systems","version":"1.0","type":"link"}