I have a brand new AR 15 that I just finished building up and I put a PRS stock on it. Only problem was, the original factory screw that goes in the rear wasn't in the package. My gunsmith installed his own though. I went to the range and it functioned, except every time the gun fired it sounded like a a slinky was going back and forth inside of the buttstock. I have another AR and it does NOT make that loud obnoxious sound with every shot. It functions fine, just sounds very odd. Any body have a PRS that makes this sound or even just an A2 buttstock being super loud and annoying like this?