I zero at 15, my point of impact doesn't change very much out to 25 maybe a 1/4 inch, that could be me, most of your shots are not going to be that far
I had the same problem with a 45 edge, Mine came with a recoil master in it, I took that out and put a standard guid rod and I believe it was a 17 pound spring I put in it, and I had tuned mags,after that mine ran fine,