is it me or has no-one read the question properly, he's asking what kind of fluctuation is to be expected. not "i have velocity fluctuations what could be causing it?"
i would expect +/- 5-10 fps (eg 285-295) depending on paint, and how clean the gun is. but assuming all else is well.
cockers, as said, arent that consistent. but they should be quite good.
is it me or has no-one read the question properly, he's asking what kind of fluctuation is to be expected. not "i have velocity fluctuations what could be causing it?"