Don't use the full choke, the imp. and mod. chokes will be ok. as for the deer size. Your good to go, the slug has alot of knock down power, but believe it or not, it doesn't do as much damage as a high powered rifle. Yes there will be damage, but in my past experience, it punches a hole thru them, without exploding like a high powered rifle will. But differant designs will do differant damage. I use sabots, and solid copper hollow points by Remington. But have also used Fostner type rifled slugs in the past. Place your shot right, and youll minimize your spoilage. hope this helps. Scott.