I have read more then a few accounts of defensive use of the 40 on real big critters like bears and moose in AK!!
In PA some years back a huge bear was killed with a 40.
My biggest has be about a 50# Coyote.
But I picked up a Ruger PC and its ballistics are more then many 10mm loads from my hand guns. So Id use it inside 100 yards NO PROBLEM!!!
CW
