I'm looking to pick up an inexpensive (<$125) chronograph, and noticed that there are many to choose from in that price range. Does anyone have a recommendation of a good one to buy, or to avoid?

I'll use it initially for my son's potato canon science project (testing velocity and calculated energy effects of three different propellants at different doses), but will also use it to test reloads in both handgun and rifle calibers. Been reloading for years, but have limited exposure to chronograph usage other than safety checks of paintball velocity prior to entering field of play, and even that was 15 years ago.