You said you documented everything you did. Did you not clean between each shot?? If not, that could have been an issue.

Guns are different. Yours may not like 70 gr of powder. And I NEVER shoot farther than 30 yards until I find an accurate load. Why shoot at 100 when you are not getting good groups at 30??

I already told you what I would do in my post above. And none of it included shooting 70 gr. You shot quite a bit but you didn’t experiment.