You may want to look at Tuckahoe state park I know it has a rather large deer herd. I am not sure if you can use a muzle loader there but I believe you can.
www.dnr.state.md.us/publiclands/eastern/tuckahoe.html I used to bow hunt ther with pretty good sucess. It is a little farther than you were wanting to go. It is an easy trip to get there from baltimore.