Greasers as patched?

I have a question....a gent I know casts for a Gibbs muzzleloader often and has said I can get some bullets from him. They are of course grease grooved, but are close enough to to be sized down if the .446 bullets work. Will the grooves effect the patches? Could they be used well enough for hunting? I am not, not ever will be a competitive shooter, and am much more a hunter, plinker, bit if they will work and I can get them inexpensively enough why not gopher it?

A GG bullet for my Gibbs rifle will work just fine in my Sharps rifle if I full length size the case so the bullet will be held securely. You could also size the bullet down and patch it. The gg’s won’t hurt a thing. But I normally use a 440” bullet patched up to .004” under bore diameter for hunting. I would try using the bullets just lubed and sized to .446”. Give them a try.