The only thing I could see going wrong is when you hit a guns/hop-ups limitations. For instance your gun may not handle 0.30g BBs very well. So chronoing that gun with that BB might not work. Though, you should be able to tell when the BB just flops out of the barrel. Once you cross a guns effective BB weight threshold, it should act similar to a gun with no hop-up.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē