Hobbyguymain, names don't always lie and in fact I am building a DR as well. (470 NE on a Huglu 12GA, nearly complete with regulating). However this particular post is relative to a future project (single shot break action).

Lots of good cartridge suggestions. With a little more information I am sure you can see why my orginal post was relative to a low pressure round. I'm thinking about something smaller than a 30 cal. since I have a 470 ne and a 300 Win.