If you mean using copies of the selected object as projectiles,
that won't work! Except for items, players, and vehicles, you couldn't even get anything else to move. The whole thing would be a Bad Idea, as the spawned objects wouldn't be attached to bricks so couldn't be removed. Furthermore, they aren't projectiles, so you would have to spawn a new object, copy the important vars of the old object(But you can't rely on the old object even existing, so you must copy them when you select it), apply them to the new object, place the new object in front of the shooting player, not shoot if it would spawn the object inside of something (Interiors and terrain probably won't respond to anything but raycasts properly, so you must correct for that as well.), then fling it in the correct direction with the correct rotation (Ever seen the rotation system? It uses imaginary dimensions. I'm sure it's wonderful to work with, but even Badspot himself didn't understand it for a long time (
See this post: "...and a quaternion was something entirely more complex like a double ended 4 dimensional cone with a spherical base..."), so have fun getting the rotations correct), oh and did I mention you need to put the spawned object just in front of the player, far enough that they don't intersect, but as close as possible?
It's not impossible(Unless you want to shoot bricks, too), but the ammount of effort it would require is *massive* compared to the average other add-on, and it would be far more likely to be failed than something with more immediate usefulness, like a cool particle set or yet another door pack, or even a unique and fun gamemode.