Ok, so my magneto speed went on the fritz, was a frustrating day, didn't accomplish much ha ha. I ended up ditching N570 as I only have about 1.5 lbs left, and I'm not having any luck getting more, though 91 grains did shoot pretty well, at around 2860 I believe. I bought a labradar, just got out today, and did a max pressure work up with Retumbo and IMR7828ssc, ended up with this -
250 SBDII
Peterson brass
GM215M
.025 off
24" Lilja 4 groove barrel
RETUMBO -
91 - 2862
92 - 2903
93 - 2924
94 - 2963 - discontinued, entire group right at 1 MOA ctc, with 91-93 being sub .75" @100
IMR7828ssc -
86 - 2922
87 - 2962 - discontinued, the two were 2" apart
If I was going to continue IMR7828ssc, I would start around 83 grains and work up from there, probably around 2820-2830 to start. I'm going to continue my work up with retumbo, likely doing a ladder from 91 to 93.