The doublerifle has its place and time as for hunting. For me the ideal double is a heavy caliber rifle for close encounters of 50 meters and downwards. Once distances gets over 100meters, my scoped and ironsigted .416Rigby offer more versatillity. If I were to go to Malaysia shooting elephants in the thick jungle, a heavy bore a la 10 or 8 bore would shine. Its the conditions of the terrain, thats desides for me, what batteri is ideal. A scoped hammerless in .577Nitro could offer veratillity..Ironsights for close range work and the leftbarrel( rear trigger) sighted for 175 yards using scope..but then again its all a compromise, if no other guns was available here and now.