Yes, the Burris AR-536 Prism 5x 36mm Tactical Red Dot Sight will work on a rifle chambered in 350 Legend or 300 Blackout. The Ballistic CQ Reticle is designed for use with 5.56 or 7.62x51, but will work with other cartridges. You would just have to sight in your rifle with the Burris AR-536 Prism 5x 36mm Tactical Red Dot Sight and understand what holdovers or adjustments you need for that cartridge.