Here’s some sub data
Seekins SP8 w/ 8” barrel
Magnetospeed V3
Berry’s 220 gr .300 Blk SP
Starline brass
FGMM 205M
A1680 11.5 gr
BTO 1.6620
Approx 980-1000 fps
Hornady 190 Sub-X
A1680 11.0 gr
GM205M
COL 1.3580
BTO 1.635
1040, 1003, 1011 fps
Hornady 7.62mm 255 Sub-X resized to 0.3080 with Lee resizer
A1680 10.6 gr compressed
GM205M
Starline brass
BTO 1.5780
COAL 2.128 approx
978, 1002 fps, didn’t lock bolt
Super data
Hornady 150 ILSP
New Starline brass
A1680 21.5 gr
GM205M
COL 1.3580
BTO 1.610
1777, 1807, 1818, 1804
1808, 1825, 1831, 1812, 1815 SD 15.3
Speer 125 gr TNT
A 1680 21 gr
Fed 205
1776, 1769, 1753, 1778, 1840