Posted right after we completed challenge. I can confirm we all got 320 artifacts and 4 320 machine guns and 2 320 snipers. We also received the normal raid 310s. What we did that I can remember and this is prior to knowing challenge was up we were surprised by loot. We downed him in two runs did normal hard strategy, started right on first run then went mid second. I had mark first run and another guy had it second. No one died. This is all I know.