It is designed to not only expand but also fragment. I see possible issues with jamming as if feeds, snags or catches could cause it to open up in the gun making a regular jam look like nothing, and I question the stability in flight beyond a few feet. Next issue is that throughout self defense and hunting the idea is to get both expansion and retention. You want the maximum diameter cutting with the maximum weight pushing. What happens to the mass when the petals all fall off?
As for their claims that it acts like a holesaw on contact ... Yea ... Right. This bullet will be spinning with regular rifling twist, and I don't see that it is going to just press against a surface and "saw" its way through.
I have read where some people are throwing hissy fits about it being deadly. It is a bullet that will be moving between 800 and 1500 feet per second. It had better be deadly!
Cost??? What is the price going to be for bullets that are from solid copper stock and crafted on CNC?