Tfox, your speed didnt change much for your arrow weight increase. My old bow was shooting a 365 grain arrow at 310 fps I could hit a 4 inch target aiming dead on out to around 37 yards.My new bow is shooting a 358 grain arrow at 290fps and I cant even hit that 4 inch taget out to 30 yards aiming dead on. My point is regardless of arrow weight that 20 fps makes a big difference in trajectory.