They use their own powder,,it may be different then the powder you use, that variable alone will change POI.
They are going to use the best preforming least expensive powders they have experimented with,,and they
ain't gonna tell ya what it is,
.
The olde, "I'm gonna replicate a factory load,," is/has been tried and done for decades,,But I started loading so I could get
Better Than factory loads,
I took apart a Win Supreme and found a blended powder, some ball, some flake all mixed together.