On all of the bullet and powder books and websites, the subsonic data always lists just MAX load data (or occasionally just MIN data). If I'm picking load data that only shows a MAX, how do I know how much can I safely back off of that?
I want to load 300 BLK subsonic. Right now, what I'm looking at is the Hodgdon website reload data. I'm going to load a 220 gr (have both Berry's and Sierra bullets) with H110 powder. This is what the data shows:
Hodgdon H110 .308" 2.260" COL MAX - 9.2 grs. 1,046 fps 28,100 PSI
Do I just back it off 10% and start at 8.3 grs?
I've not loaded for subsonic before.