The scene is set at night and there’s this kid or teen I think it’s a boy who’s out for revenge and he’s been going around killing people who have hurt him or his family in the past. This particular scene is shows up to this guys house and tries to kill him but the guy manages to escape out back to a wooden shed. In the shed the boy kills him with his final bullets or something like that and he conveniently finds the guy’s stash of weapon in a metal cabinet in the shed and he arms himself to go off for the next target. This is before the last climax of the movie and after the end before the credits it shows that he has managed to hide/dispose of the body in the shed and is regularly using the shed as a base for weapons.

That’s what I remember from the movie, if it sounds familiar to you and remember bits and pieces feel free to add on. Thanks!