OK I got to 28" took about another 1/2" set. So 40#@ 28" shot 184fps 3 times. Then if I did it right went back and measured the draw weight at 24", it was 33 ish pounds. Ran that through Steve's formula and got 274 grains. Lightest arrow I have is 294 so I used that and got 162fps twice. I just did two because that arrow don't fly worth soup. So 178,184 and a questionable 162. 20 grains diff, maybe in the 170's
There ya go!
Oh, the 40@ 28 was with a 396 grain arrow, closest i could get to 10gpp.