You need to try both because it depends on the individual gun and how much powder you are using. The 44 loads 10 times easier than the 45 in my Encores and the accuracy is the same. I have a friend who cannot shoot the 44's in his Encore because they keyhole.
The 44 is not a high pressure sabot and the 45 is. If you are dumping 150 grains of powder down the barrel the 45 might be needed. I only shoot 80grs of 777 in mine since anything I have shot has been plenty dead with that. I have shot mine with 100grs of 777 and had good accuracy.