IMO if your looking to use a 40 in the woods for self protection it's not gonna matter. I'm not a ballistics expert or anything but i think it's just too smal of a round for anythign that woudl cause you danger besides tweakers. if you are concerned about something like a bear though you shoudl probably go FMJ for the penetration factor. you won't get any expansion out of it but i guess it's better than throwing rocks. I personally carry a 357 mag as a side arm in the woods when i'm not carrying my rifle. Even when i have carried my 45 i did it with the understanding that it was not ideal for dangerous critters with more than 2 legs.