Depends on your state I guess. In many states a 9mm is not allowed for deer hunting. not sure .40 would be either. here in VA, we are allowed to use anything bigger than a .22, but when I lived in ND, we could not use anything smaller than .357, but now it has changed there to be anything bigger than .35 caliber so 9mm would be ok.
Anyway, double check your regulations, don't want to get in trouble with johnny law out in the woods.
“A government big enough to give you everything you want is a government big enough to take from you everything you have.”
Pres. Gerald Ford
Address to a Joint Session of Congress
August 12, 1974