My chronograph got here today and i did some testing and think i got a lemon. My first shot read 1005 fps then the next read 950fps followed by 937, this is before adjusting anything. I would say 60% of my shots failed to read and gave me an error and then when it did read the consistency was terrible. I ended up adjusting my hammer spring 3/4 a turn and it read 890 fps and then 900. so i just left it at that and proceeded to shoot five groups and my grouping was excellent with the 25grain jsb's and i got almost 10-15 more shots before going under 130bar. I still got extremely wide spread on my velocity readings after adjusting to 890-900fps some would just jump to 930-940 then down to 860. I'm not gonna touch anything else and just return this chronograph and spend some money and invest in a quality chrono. Pretty frustrating day to say the least.