The Sigma VE series has a very heavy trigger pull. If you're not used to it, it can induce a flinch as you muscle the trigger, and with the long, heavy pull you have plenty of opportunity to anticipate recoil to generate a classic flinch.
I have the Sigma VE in 9mm and it takes some getting used to. Overall, though, it is a reliable and accurate weapon. I would try some shots from a sandbag and get some other good shooters to do the same before I monkeyed with the sights. Just my $.02.