That short Division prequel film Ubisoft did (I think I saw it on amazon, maybe hulu) actually has some really nice gunfights. Awesome detail stuff like buckshot making several small holes through a wall instead of just blowing a nice circle through drywall and good use of cover and team coverage while approaching a target.
Way of the Gun is awesome as well.
Anything Michael Mann, namely Miami Vice and Collateral and of course Heat.
Lots of asian war films are really good, they focus more on the large spectacle and less on hero characters mowing down mooks by the dozen.
These days basic gun handling, magazine changes, shouldering the rifle instead of firing from the hip, some use of sights, etc are pretty standard. We've almost gone too far with characters loaded down with TOO MUCH tac gear such that the actor, particularly these 100 pound slim women, struggle to even move or maneuver the weapon