Most people are either disappointed or question the chronograph when they check their bow speed. Any draw less than 30" you will lose approx. 10 fps per inch, anything added to the string robs speed, any poungage less than the max. for that bow approx. 4fps loss per pound. Several years ago my buddy and I were switching a friends bow over for 3-d looking for alittle more fps out of it and we gained 12fps just by replacing the brass clamp on nock point with a tie on nock removing the peep aligner rubber and taking off the cat whiskers. Most of the speeds that are advertised for bows are shot at 30" draw, 70 pounds, bare string, and a bare shaft. That is the IBO speed quoted in most adds.
add a sps system to quiet it, remove everything except a regular peep and string loop. switch to a lighter shaft and a lighter point.
see my calucation below? thats a 7.4 grain per inch arrow, 85 grain point 29" cut length, 2" blazer vanes. ive got enough KE to kill a bear at 61# draw weight. need a 500 grain arrow when you want to kill a water buffalo, not a whitetail.
the exception is of course a recurve, you need the heavy to compensate for the lack in speed.