This is what we use
Shooting F-1 Chronograph
Shooting Chrony's F-1 Chronograph gives you exact ballistics at an affordable price. Check velocities ranging from 30 fps to 7,000 fps to within 0.5% accuracy for any projectile, including arrows, bullets, pellets, etc. An LCD read-out stays on the screen until the next shot is fired. The F-1 is the basic ballistic work horse, with the option of upgrading to any other Chrony-model should you want more features anytime later. Constructed with a steel housing for strength, durability, and less expansion/contraction deviation than plastic housings. Weighing in at under a lightweight 2.5 lbs., the F-1 folds for safe carrying and storage. A manufacturer's three-year warranty is included.