Not the best for hunting but I have the old standby Lyman 173gr RN 30 cal mold and it shoots fantastic in both of my 336 30-30s. One is microgroove and the other Ballard. I size them to .311 and usually launch them with Trailboss but have used other powders for full power loads and they were still accurate. Be sure to slug your bore and keep the bullets a little over bore diameter with the microgroove barrels. Veral Smith's book has some good info on shooting cast in Microgroove barrels. He even preferred them over many other rifling forms.
