If a pistol then there would be difficulty either with obturation (if bullet cast under size to allow it to be muzzle loaded) or with loading (if bullet cast to correct size and hence oversize for muzzle loading).

If a revolver then I see no particular reason why this would not work. 230 gn (presume .44 or .45 cal) is a lot heavier than a ball, so some load adjustment might be needed, and of course the twist rate of the barrel might be far too low to stabilise such a projectile - or is it one of these new fangled nitro muzzle loaders (which I presume have a faster twist than a BP gun)? Still it could work.

In BP guns it seems that balls work a lot better than bullets but it is worth an experiment.

EDIT: This post underlapped some other responses. The proposed firearm is a revolver and not a pistol. The Euroarms R&S is a good gun with balls, I see no advantage to using bullets in it but you might be fortunate. Worth a try anyway.