{"product_id":"cmmg-mk4-ar-15-upper-receiver-assembly-midnight-bronze","title":"CMMG Mk4\/AR-15 Upper Receiver Assembly - Midnight Bronze","description":"\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003eCMMG Mk4\/AR-15 Upper Receiver Assembly\u003c\/span\u003e\u003c\/strong\u003e is a drop-in platform upper for any mil-spec AR-15 lower. It is machined from \u003cstrong\u003eforged 7075-T6 aluminum\u003c\/strong\u003e, fitted with \u003cstrong\u003eM4 feed ramps\u003c\/strong\u003e, and finished in a durable \u003cstrong\u003e\u003cspan style=\"background-color: #ffff00;\"\u003eMidnight Bronze Cerakote\u003c\/span\u003e\u003c\/strong\u003e. The assembly ships complete with the \u003cstrong\u003eforward assist\u003c\/strong\u003e and \u003cstrong\u003eCMMG ZEROED polymer dust cover\u003c\/strong\u003e already installed, so builders can drop it on a lower without any small-parts bench work.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003eThe defining feature of the Mk4 platform is its \u003cstrong\u003eenlarged ejection port\u003c\/strong\u003e, which lets a single upper run a wide range of pistol-caliber conversions - including \u003cstrong\u003e9mm, 10mm, .40 S\u0026amp;W, and .45 ACP\u003c\/strong\u003e - in addition to standard rifle calibers like \u003cstrong\u003e5.56x45mm NATO\u003c\/strong\u003e. That versatility makes this upper equally at home as the foundation for a custom build or as a direct replacement for a worn factory upper.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cspan style=\"font-size: 14pt;\"\u003ePair it with a CMMG barrel, handguard, and bolt carrier group in the same Midnight Bronze finish for a coordinated custom build, or use it as a premium replacement part on an existing AR-15.\u003c\/span\u003e\u003c\/p\u003e","brand":"CMMG","offers":[{"title":"Default Title","offer_id":55292118401346,"sku":"55BA290MB","price":125.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0997\/7921\/5682\/files\/alt_146873bd-e75f-4331-b973-138121b51fbf.jpg?v=1785102609","url":"https:\/\/centerfiresystems.com\/products\/cmmg-mk4-ar-15-upper-receiver-assembly-midnight-bronze","provider":"Centerfire Systems","version":"1.0","type":"link"}