I have never used a 30-30 but have used .32win spl which is very similar. Usually 150 gr works fine. Only use in deep woods. Open areas I use a .243 80-90gr. If deer is within 100 yds neck shot drops them in their tracks. Big bucks I shoot for the heart and follow trail 75-150yds for trophy. 243 to me gives a better chance for a second shot if necessary(can keep scope on deer at all times).