Lesson for next time. Do not buy "Mickey Mouse" optics outsourced from who know where and from whom. It pays to stay with well-established experts in the field: Trijicon, Aimpoint,.....
Speer Lawman 147 shot consistently high for us, across many pistols. The Lawman 124 solved that problem and was more accurate, too.
ETA:
I'd try different ammo before I started shimming a dot on a reciprocating slide.
I'd listen to Blue