I opted for the 7 over the 300 for my personal preference... to me the 30 cals don't shine for longer range applications until you get over 180 grains, and the WSM cases just aren't ideal for the heavy for caliber bullets. The 7WSM case also holds a couple grains more powder over the 300
I'm using reloader 22, IIRC 67 grains
The Wyatt's box let's you get a COL of 3.00", so one can seat the bullets out of the case a little farther to make more room for powder.