Along with counterfeits - I collected the Bust Half Dollars as a kid. I still have 60 or 70 of them. There are several dates where
Strike Doubling was a real problem. It was caused by wear in the machinery. It shows most prominently on the profile. I believe I also have one dated 1824 with a seriously "tripled" profile. If you refer to page 622 of Overton's "Early Half Dollar Varieties" you can read his explaination of this rather common feature seen on many dates.