First off congrats on your first buck and witha ML to boot...excellent!

Your shot was the femoral artery and I have seen it on a few occasions. In fact last fall one of my buddy' s put down his PB that I rattled in for him. He was so nervous he missed the broadside shot at 100 yards but connected on the second fleeing shot with the femoral artery. His blood trail was specky but you could follow it decently due to snow cover, he made it further than yours at over 300 yards and required one more to finish him off, as he was still moving but couldn' t get to his feet. It happens to us all and you recovered it so that is the most important thing. Enjoy your meat, horns and memories!