The last time I was at ASCA, Miles took his 1.5 to a flash hider and his seemed to fit perfect. He must have the magic touch
I had the allen key with me that I tried, and it seems the problem was with my set. I suppose the set I was using wasn't of the greatest quality because it was a little rounded.
It seems a lot of other people are finding the screw is soft so I will just keep my flash hider on witout the screw. It sounds like it's going to be a pain if it ever gets REALLY stripped.