using jbm I usually get very good info, but today it was way off with my proven load. Normally at 300 yards it's running about 1.3 mil today 1.7, 500 usually 3.5 today 4.2, 600 is normally 4.7 today 5.7. This is verified by two different rifles running the same speed 2586-2600 fps, same dope at all ranges. baro was at 30.02 temp 63 elev 670 wind at 10-15 at a 90 degree, both rifles are the new aac-sd 20" shooting an178 Amax,