The Delmarva silver fox squirrel has been a protected species since 1967. Weighing up to three pounds, they are meaty critters. Their habitat was originally pennsylvania, delaware on down through the Md eastern shore and virginia. They are now mostly on Md eastern shore and VA due to habitat destruction. I used to hunt deer when I was younger on eastern shore and the Silver fox squirrel was plentiful; I haven't seen one since 1973.
AOA has a calculator to determine your fpe and fps on the left side of there web home page. It works well.
How do you determine what fpe your rifle is shooting?