I measured the speed of feather fletched and blazer fletched one afternoon out to 50 yds. I am going on memory but the difference was 1-3 FPSdepending on which arrows you compared (the fastest blazer with the slowest feather). But lets say there is a 10FPS difference. If you are shooting 240 @ 50yds with blazers then feathers will be 230. That is more than enough speed and KE to kill deer. So, is speed really an issue?