I have never seen a surefire sf3p 3 prong flash hider 1/2 x 28 on a sig 516 14.5 or 16 inch upper , the thread pitch is 1/2 x 28 on my 14.5 in Reading a 2019 compatibility chart it looks like they are compatible for the 10.5 516 , but not listed for 14.5 , why would this not work on my 14.5 ? I placed it on and hand tightened for pics. Thanks for any help.