OGH,
I've taken a couple with my 40 and half a dozen with my 38 cal. You have to get within 30-40 yards, be accurate, and have the discipline to let deer walk. I let a big 8-9pt walk a couple years ago because it was 50 yards out.... wish I would have had my 54... Anyway, back to your question..... Shot placement is critical and I always aim a little below the ear. As far as tissue damage.. it makes a mess... a lot of hard stuff in that area of the body.
SP
For what it's worth....I hope this doesn't sound condescending but I never recommend that low of caliber to anyone... I just don't trust them.