Possibly make a file/code specific for revolvers that makes it fire a long red line from near the barrel that does no damage and doesn't register, and alternate fire could turn it on or off(known as flip for swords)? Or, we could possibly make it so that instead of having a visible laser, you would have a little bit of a light at the end of your gun, and a red dot showing up where you're going to fire. Just ideas... I'm not completely sure if it would work, let alone if anyone would be willing to spend the time to code something like that.
