I'm having a difficult time finding good data on case head expansion for the 300 Win Mag. I'm using Nosler brass with Winchester magnum primers. I'm slowing working up my load in 0.5 grain increments. I have a micrometer (0.0001). After one firing, the case head expansion average is 0.0015 +/- 0.0002. Similar finding from 70.5 grains to 72 grains. Maximum load is 72 grains. My primers are a little flat but THEY ARE always flat even at my starting loads (65 grains) and they DON'T appear any different. No visible powder around the primers. No craters on the primers. No case head extractor marks. Bolt lift is unchanged. I'm concerned about the amount of case head expansion (on the belt) after one firing. Mostly because I can't find any good data on what is normal and when I should be worried. I would love a good velocity hunting load but not if it's hot. Plus I would like to get as many reloads out of the brass as possible.