A man is chased and shot in the shoulder (some blood seen).
A man shoots two men in an apartment, and engages in a long shootout with more men in a stairwell and parking garage, and he shoots all of them (mildly bloody).
Two men engage in a fight, and a woman shoots one in the back (bloody). The woman is clubbed with a board by another man, and the first man knocks another man over and runs away as other men shoot at him.
There's a brief bar fight.
There's a large shootout in a parking lot, and several men are shot.
Two men chase some bad guys in a truck and shoot at them, and bullets cause several cars to explode. One man is hit in the back with a bullet and falls off of the truck.
For a movie serving up four bona fide action stars as protagonists, there's not nearly the amount or quality of fighting and shooting that their fans would expect. Kelly, the great martial artist, is grossly underserved by the script.
Most of the hard R/18 rating is because of the violence. But to how extreme it is, is debatable. The movie is liekly closer to its original 15 (in the UK)/moderate R rating. It's so comical in nature. The movie feels like a buddy action comedy with some Mafia elements.
There's a fight between a man and several other men in a hallway.
There's a large final shootout in which many people are shot, and an explosion occurs, catching a man on fire.
A man fights several men, and they gang up on him and beat him up. He's later shown unconscious, with some blood on his head.