IMO if you're shooting saboted bullets, they are gonna' be a mite short for long range stability. You might want to work up a load with a heavy conical. A minie ball type with hollow base would probably be more stable for long range work.
Ahhh I must disagree with this one... There is no way a minnie ball is going to be more accurate at long distance than a ballistic tipped sabot. Now you obviously need to find one that your gun likes.
I shoot the Barnes Expanders TMZ in 290gr in my Encore, backed by 130gr of Blackhorn 209. 300 yards inside a grapefruit is the norm.
Do not waste your money with the 25 ACP conversion kit, I have one and it did help with the 777, but the BH 209 is a so much superior powder that I will never go back to the crud ring! I have 3 lbs of 777 that will be used as fertilizer or something, but it will never again go down my pipe.