I have only owned 1 double, a John Rigby .350 No2 and it balanced better than anything that can be stated in words. It was truly comfortable to carry, shoulder and fire.
Didn't do a lot of timber or short range hunting at the time so let it go.
Made it 1912, it still shot 1.5" for 6 shots (3 each barrel) at 50 yards using the express sights and utilized .358 caliber bullets so it was very easy to load for.
