I've had a 45/410 since they came out in the 80's. If you buy one to shoot as a 410, you will be very happy with it. If you want to use it primarily as a 45, you will be disappointed. It will shoot the slugs ok, (killed a 125# boar shot between the eyes at 50 feet) but the slug is very light weight and loses what little energy it has very fast. The sights are the weak link. The bead sight on the vent rib is not adjustable and are designed for shot.
9.3x74R brass with .45 bullets could be good enough for deer to 100yds. They would be ideal for a combo small game hunt with the possibility of larger game. Use caution, a full house load is not suitable for a contender.