This is a hard thread to follow because the O.P. does not use standard shooting terminology. Or his shift key. But as best I can tell...
There is no significant difference in the range of a breechloading cartridge rifle and a muzzleloader firing the same projectile with the same amount of black powder.
In the original Creedmoor matches of 1874, the US team, shooting Remington and Sharps breechloaders, only beat the Irish team shooting Rigby muzzleloaders by one point, 931 to 930. If an Irish shooter had not shot a bullseye on the wrong target and been scored a miss, they would have won. The Irish said the only real advantage the Americans had was that their breechloaders were easier to clean and load, but were not more accurate. Ranges were 800, 900, and 1000 yards.
I don't know that anybody has ever done a study of the ultimate "falling out of the sky" range of a muzzleloading bullet versus a breechloaded bullet to compare with the Sandy Hook tests of 1879. Mr Whitworth, if anybody.
Comparing a round ball muzzleloader to a breechloader is apples and oranges, they were not from the same period and were not using comparable technology.