Labradars don’t work that well with low power .177. I have one that I never use for pellets anymore. They tried, unsuccessfully, to use one for tech inspection at the FT Nationals and other matches in Phoenix.
Mine works great for larger projectiles. Very poor for .177 FT rifles. I would not spend the money on one
i have a Competition Electronics Pro Chrono in my shop, and carry a Combro to matches. The combro can be calibrated to match other chronos. Mine reads within 1fps of my pro chrono every shot. When using it in the field...it’s important to understand that the body of the unit is plastic and expands and contracts a great deal with temperature. If the unit is sitting in the sun and is 100 degrees...your reading will be slower than it would at 70 since the sensors are further apart after expansion. Just something to keep in mind. I have not found that to be a problem.
I don’t find it necessary to chrono check all the time. I only do it to verify I am not over the fpe limit if I go to a new elevation. If I am hitting where I am supposed to be hitting at my zero and 55y...my velocity is good. Don’t get hung up on the actual numbers. Zero the gun at 30....check elevation at 55. If you are a little high at 55....lower the speed a little. Little low at 55y....raise speed a little. I only need to do this because I shoot at 6500’ at home , then travel to most matches much closer to sea level.
I have found that I can use my same numbers all across the country by just altering speed. I run about 765-770 at home, and 785-790 on the road to make my 55y elevation work in the heavier air. Since there is a 2% allowance in speed for FT...I am well below the max velocity that would disqualify me (815).
Hope this helps.
Mike