Bushmaster .450 20-Inch Inch Barrel With Flat Top Complete Upper Assembly Comes with complete upper assembly Comes with black free-floating handguard Hard chrome rifling on the bore is great for longevity Expensive $340Shop NowClick to read my review ...
The Sharps Bros. upper is compatible with multiple AR-15 calibers, including .224 Valkyrie, 6.5 Grendel, .300 Blackout, .223 Remington, and 5.56x45mm NATO receiver. However, due to the size of the ejection port, it cannot accommodate rounds such as .458 SOCOM or .450 Bushmaster. ...