I don't make habit of questioning the ability of others without reason...
Extraordinary claims without extraordinary evidence is good reason as is the changing of the 'facts' with subsequent tellings.
Fine shot shot with your air rifle when there was no pressure, nobody's life on the line, no witnesses. So you made your first shot. Stacy claimed to have as well, only we now know he didn't. He did have witnesses or at least forensic evidence that will indicate more about how he actually shot. I am sure it was a long way. He says he shot the guy 5 times in a row. We shall see if these claims hold up. Right now, nobody has verified any of them other than he did shoot Conner and is credited with saving at least one and potentially several lives.