Magnum Research Barrel, .50 Action Express, 6, Picatinny Accessory Rail, Fits Desert Eagle MK XIX 50AE, Black BAR506 Desert Eagle MK XIX 6" barrel chambered in .50 AE. All steel construction. Available in multitude of finishes. Picatinny style accessory rail. Simple installation (when switching from .357 magnum you will need to change the bolt assembly). Please refer to the DE owners manual for installation instructions.