Hoping I do not offend I will take the discussion further.

I agree that stock fit and weight are critical but should we be open to other options to inprove the shootability of Doubles? Are they perfect as is [like art] or there other modifications that could help?

Maybe with options you could shoot a 577 intead of stopping at the 500NE or move up to a 470 from a lesser caliber.

I agree that mercury "tricks" are not acceptable and I don't like how the guns shoot.I do like porting in other rifles as it lessens the muzzle rise and keeps the gun on target better. I think that muzzle brakes would be a technical mightmare but I have them on other guns and they are noisy but efficient. Stock mounted spring dampened recoil devices work well in Shotguns by extending and changing the nature of the recoil curve over time like shock absorbers on your car. Truly ugly, but simple and efficient.

At the risk of raising a stink and being tarred and feathered--
Should any changes that ruin a Doubles fine lines be taboo or is better shootability something to strive for? Can we make them better in this respect? Who knows?

I would luv to shoot a 577 but lacking any recoil assistance and with it delivering 120 ft/pounds of recoil to abuse my brain,retina, bone and tissue, I think I'll pass and stay with smaller doubles with faster 2nd shots.