From my experience Stock Doves are smaller than ferral pigeons and when they land they give a distinctive whistle from there wings, we have a lot of them on the shoot where I go and they are much more "switched on " than other pigeons. if in doubt DONT SHOOT you cant call a pellet back. Just go for the obvious ones, ps collard doves give a cooing sound when they land and are a dark sandy colour with a black collar.
ATB Bobb D