The difference among killing power of a .25 vs a .30 and a .367 cals Airgun rifle are huge in terms of "Hunting Energy Units" (HEU's) A .25 Cal at 60 fpe gives 580 HEU's A .30 Cal at 90 fpe gives 1070 HEU's A .357 Cal at 132 fpe gives 1900 HEU's HEU's include damage in tissue. Fpe is just...