You need a new daycare provider. I understand that they can’t allow children to mimic shooting Uzis or machine guns but here’s the reality. Boys developmentally try to figure out where they “fit” amongst other boys. Playing roles of dominance or submission is common and developmentally appropriate. In fact, Bruno Bettelheim wrote extensively about the importance of the imagination in play.
We have become so frightened, that we are even afraid of normal behavior of 3-year-old boys. What boy doesn’t want to march through the woods and pretend to hunt bears and lions? You can take all the toy guns you want away from boys and they will find weapons to “shoot” with- sticks, rocks and their fingers.
Here’s what I recommend. If you don’t have the option to change daycare providers, then talk with your son about home behavior and daycare behavior. Tell him that finger pointing and “shooting” at school can’t be done. Second, make sure that you he isn’t watching violent video games (or other programs) with shooting at home. If you have a yard, take him out and tell him that this is the only place to shoot his toy gun. Make a target and let him shoot at it. Then, when he is finished, make him put the gun away. This way you are teaching him to respect guns, shooting and people.