After eight years of anticipation, the Bushmaster Unicorn, also known as the ACR caliber conversion, has finally hit the market. This caliber conversion system for the ACR, a platform that offers fully ambidextrous controls, improved ergonomics, a gas-piston operating system, and tool-less configuration and caliber adaptability, is promised to be the first of many conversion options. For now however, these conversions will be offered in .450 Bushmaster, and 6.8 Rem. SPC II (see specifications below). For more, visit Bushmaster.com.