Something In my #5 Cylinder?

Thanks for the reply guys. Bore scoped again last night and found a chunk of #5 piston is gone. See picture below. Well, regardless of what happened I'm pulling the engine this weekend. I did Drag Week this year with this new combo. I think I was running too much timing and got into some detonation. Backed the timing way off and now had the tune just right but I think the damage was already done.

Boost learning curve I guess. I'll inspect all pistons and bearings but maybe I'll get lucky and only need to replace #5 piston rings and bearings? We'll see. Hopefully the head isn't also hurt.