Hilariously, Trijicon will say 308, but they refused to confirm if that includes SCAR rifles. Try it .. you'll get a dead pixel. Ask me how I know
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For further clarity, I asked 3 seperate times your exact questions, and Trijicon's Support team "looked into it" and never responded. Pretty fun.
ETA: My SCAR kilt a pixel. Don't SCAR with your UTC12.