I just got a new AR-15. Upon field stripping it and re-assembling it, the first function test action is to depress the trigger causing a dry fire. Now is this going to hurt my rifle? Would it be better to buy some dummy rounds to absorb this action? Or is it just fine to dry fire it? I do not want to mess my rifle up. Any help would be appreciated. I have seen so many mixed messages on what is appropriate and what is not.