Above advice is all good. Only thing I would recommend is you find a gun that shoots Blackhorn 209 powder well, right out of the box (or with minimal tweaking.). Since you have been hunting quite a while, I'll take a chance and assume you have centerfire rifles. BH209 cleans with the same stuff you clean you other firearms, making the transition easier. Then if you want to try the other powders you certainly can.

Do a search on this board to find out more about the different powders you can use with a ML.