One double for me would have to be a medium weight scoped 9.3x74r. By medium weight I mean around 9# loaded with scope of about 1.5x5 in claw mounts. Set trigger on one barrel. Make of choice would probably be Heym, ejectors with selector switch. You would then be well equipped to take ANY game in the world from closeup out to about 300yds. Not too heavy to carry all day not too much recoil to shoot all day.