Before I pull the trigger, I wanted to run a sanity check with you more seasoned members...
Lacking any industry heavy load data for the 10mm, I read what I could find and determined (in my mind) a safe starting point, using the powders I have on hand. All are using new Starline cases and WLP primers. My boolit drops at 223 gr from a MM 220 gr mold.
1. 4.5 gr Tightgroup
2. 7.0 gr Longshot
3. 9.5 gr WC820 (Lot#47321)
I'm guessing the surplus powder will probably be best for the heavy bullet, but in hindsight, I probably should have gone with CCI 350 for that load.
Thoughts?