I dont know about using a patched ball but I use .457 round balls with an ordinary black MMP sabot in my Savage with smokeless powder (IMR 5744) for plinking and as a varmint load for Jackrabbits with good to great 100 yd. accuracy. I imagine that round balls would work as well, or maybe even better with BP or one of the substitutes.
I also tried .451 and .454 balls. Accuracy was at least as good as with the .457s but the looser fit in the barrel caused too many misfires when using smokeless. That problem shouldnt exist with BP or a substitute.
The .457 ball weighs something like 146 grains, recoil is light and fun to shoot and I found I could cut the powder charge way down for my ten year old grandson and still maintain accuracy.
For general information or If any of the Savage shooters on the board want to try round balls with smokeless, Heres what I use: For jack rabbits and hundred yard plinking, .457 ball, MMP black sabot, 50 grains of IMR 5744 measured in an adjustable BP measure. This equals approximately 45 weighed grains. For light loads I use the same components but cut the powder to 30 grains, measured.
It's been several months since we last used the light loads and to be truthful, I can't remember whether we were shooting those at fifty or a hundred yards.
I use the 5744 because it is much easier to ignite than most other smokeless powders. And, since it takes a relatively large variation in load weight to produce any significant change in point of impact, lends itself well to measuring .