How to barrel mount a Streamlight Protac HL-X weapon mounted light. I recently decided that I needed to put a white light on my AR 15 style rifle. I keep my AR-15 ready to go by my bed, ready to defend my family should it become necessary. The end result was a barrel mounted Streamlight Protac HL-X. I also realize that if I would need to use a firearm for self defense, it will likely be at night, or perhaps…