Ruger AR-556 MPR 5.56 NATO/.223 Remington Semi-automatic Rifle It's the wildly popular AR-556, but with a few key enhancements that make it easier to shoot and easier to love. Like the original, the AR-556 MPR is built around a forged 7075-T6 aluminum receiver and cold hammer-forged 4140 chrome moly barrel, delivering rock-solid durability and shooting performance. However, unlike the original, the AR-556 MPR comes standard with a Magpul MOE SL collapsible stock and MOE pistol grip. The original heat shield handguard has also been replaced with a much better 15 inch free-float handguard with M-Lok attachment slots. And perhaps most importantly, the original single-stage trigger has been replaced with the outstanding Elite-452 two-stage trigger, offering a crisp, consistent 4.5-lb. trigger pull and 30% faster lock time than standard triggers. Yet despite all these improvements, the AR-556 MPR is STILL highly affordable. That's a home run in our book. Forged 7075-T6 upper receiver with forward assist, dust cover, and brass deflector; Type III hardcoat anodized Forged 7075-T6 lower receiver is Type III hardcoat anodized Cold hammer-forged 4140 chrome-moly steel barrel with ultra-precise rifling provides exceptional accuracy, longevity and easy cleaning The Ruger Elite 452 AR-Trigger is a two-stage trigger that offers a smooth, crisp, 4.5 pound trigger pull. It features a full-strength hammer spring for consistent primer ignition and a lightweight hammer that enables a 30% faster lock time over standard MSR triggers Magpul MOE SL collapsible buttstock Magpul MOE pistol grip 15 inch free-float handguard has M-Lok slots at 3:00, 6:00, and 9:00 Bolt is machined from 9310 alloy steel and is shot peened and pressure (proof) tested to ensure strength, structural integrity and durability Chrome-plated bolt carrier inside diameter and chrome-plated gas key inside diameter provide exceptional resistance to hot gases. The gas key