Accuracy is all about the finding the right combination of barrel to sabot to bullet fit. No doubt if one could find the right sabot that bullet would shoot but so far I have not heard of anyone finding the right combo, but that does not mean it does not exist. Guys have shot 40 cal bullets with success with the right sabot and I see no reason that .429 bullets would not shoot good with the right sabot and powder combo.
Typically in the Savage guys either use .452 bullets with MMP black sabots or .458 bullets with the mmp orange, but there are other ways to success.