S&W M&P AR15, measurements taken at 10' from muzzle, 900' elevation.
Federal 55gr FMJ BP223BL (walmart), 80 deg., 2980 fps
Fed 55gr FMJ XM193F, brown box, 57 deg, 3141 fps
Fed American Eagle 55gr FMJ, 94 deg, 3158 fps
Wolf 55gr FMj, 80 deg, 2882 fps
Win 55gr FMj, white Box Q3131, 80 deg, 3096 fps
PMC Bronze, 84 deg, 2760 fps
Fiocchi 55gr FMJ, 84 deg, 2826 fps
Fiochhi 55gr SP, 84 deg, 2834 fps
SS-109 ammo:
Prvi Partizan, 84 deg, 2990 fps
American tactical Imports, 84 deg, 2990 fps
Lithuanian Military, 84 deg, 2997 fps
Other 62 gr:
Fiocchi 62gr FMJ BT, 84 deg, 2653 fps
Silver Bear JSP, 94 deg, 2903 fps
I didn't record the 20" data as it was my friend shooting his rifle. But, for the most part, around 150-200 fps faster.
Happy shooting.