Woodsie: I am not much of a long range pistolero but didn't the late Elmer Keith kill a Mule Deer out at 600 yards with his 44 Magnum pistol!?
I saw a friend of mine kill a Whitetail at 200 yards with his Ruger 44 Magnum semi-auto Rifle.
The Deer went down quickly and was a one shot deal.
Myself I would not shoot at a Deer anywhere past 100 yards with a 44 Magnum pistol.
Shooting silhouettes or metal gongs is another thing - it would be fun to try and bonk a gong (12"x12" gong) out at 400 yards.
I am guessing I could hit said gong once out of six times using a long barreled revolving 44 Magnum fitted with a Leupold 2.5x8 scope.
Hold into the wind
VarmintGuy