I find that the biggest contributing factor to cumshot size is how long you go without ejaculating, and then second is how long you masturbate before ejaculating. If you masturbate for a long time, but have had multiple ejaculations recently, the cumshot will be volumnous but very watery. More seminal fluid than sperm. If you masturbate for a short while, but have a lot of cum stored up, then youll cum a small amount of thick gobs.