Well I got out to the range today with the new loads. I used mixed brass. Win lpp. Zero 230gr fmj seated to 1.255-1.256. Temp was 25f. Test platform was hk usp expert 5.2in bbl. I just ended up using three different charge weights for bullseye and hp38 so I didn't have to spend too much time in the cold.
Hp38
5.2gr, SD 19, avg 805, es 62.
5.4gr, SD 31, avg 842, es 106.
5.6gr, SD 10, avg 878, es 36.
Bullseye
4.8gr, SD 17, avg 794, es 67.
5.0gr, SD 15, avg 824, es 47.
5.1gr, SD 8, avg 855, es 24.
It appears the win lpp may make a difference in burn rate for the hp38, the bullseye numbers are in line with my previous testing. It appears with this component combo hornadys data seems spot on for hp38. Using mixed brass may have increased my extreme spreads though. Accuracy was ok for the hp38 loads and excellent for the bullseye it was cold so i was shivering a bit and threw some fliers. I'll test again with same headstamp brass in the future. It looks like I'll stick with 5.3gr hp38, and 5.0gr bullseye for my bulk loading session. Picture is 5.0gr bullseye, 10 shots at 20yds.