Anything strong enough to cut metal. Because we weren't there when someone cut the edge, there's no way to know for sure what instrument did it. (for clarification, the cut occurred after the coin was in circulation)
It was damaged after it left the Mint. Only the person that created the damage would know the answer to your question. All other answers are pure speculation or guess work. The real thing with these is that the coin has been damaged and that is all that matters. Welcome to CT.
Hi Welcome to ct! Imho, looks like someone took a hacksaw blade to it. Keep looking! You never know what you might find!
