I am always amazed at the chrono results I see posted on the different forums. Folks always wondering why their $800 bow is shooting 20 fps slower than "what it should be". Now I am no expert, but I have learned a few things about chronographing projectiles from my hand loading ammo, and competitive pistol shooting for the past few years. I have had the oppertunity to learn that chrono is not an exact science, and how to best eliminate error in readings. So I figured I would share what I have learned after shooting through dozens of different chrono's across the country. To get the most accurate readings possible from your bow, try following the following guidelines. 1. Buy a high quality chrono, not the $69.00 model 2. Fresh batteries, or a 110v power source preffered. 3. The chrono light source should be infared. 4. The chrono should be put in a "coffin" so no ambient light will have an effect on the lighting conditions 5. Keep all arrows flying through the skyscreens level to the sensors, about 4 inches above the sensors, and consistanly in a 1-2 inch circle through the circles. 6. Shoot 3 arrows at a time and take the average. I can consistantly demonstrate that readings using this process will yeild 10 fps higher than shooting through a chrono on a sunny day, and 5 fps faster than using a light bulb setup on the skyscreens. The truth is, unless you have a speed "standard" you can shoot through the chrono, one can expect a =/- 10 fps error in readings.