Ok, so today I went back to the range for another round of tests. Seems like I'm spending so many bullets and powder just in testing!! It's crazy. Ok, to the point, I used my Czechmate with AA7 in all loads and loaded up to 1.165". Mixed brass.
124gr CMJ: I tested 9-13lb springs on loads of 9.7gr, 9.9, 10, 10.2.
115gr CMJ: Tested same springs with charges of 9.8 &10g.
Attached a video I made of the results even with slo mo. I will chrono the best combinations of powder and recoil spring at a later date.
Please please provide me feedback as to what you think the best combination is, based on the video. I am too close to it and have begun to think they are all the same!! lol