Your 10 yard 1.75 inch square group led me to deduce that.
See those low/left shots? Trigger press.
Snap caps randomly loaded. Also, skip the B8s for now. Go to the dollar store and buy the smallest post it sticky notes they have. Buy a black marker. Put you a dot in the center of that little note OR....a staple in the middle. Shoot at the 3/5 until you can make that dot/staple go away. Put a bunch of these sticky notes up so if you eliminate the dot/staple, move to the next one while you are in the groove. Do this with 2-3 snap caps in your mags......random....like load them the night before or load up several mags and mix them up to where you can't remember which one has the dud at shot 3 or five or whatever.
No speed in this.....matter of fact....take a lot of time focusing on the press. Speed comes later.
PM me your address. I'll send you 10 B8 repair centers. For later......when you get your press smoothed out.
Regards.