The small #5-40 x 5 1/16" set screw that Magpul supplies with their MOE trigger guard should not have thread locker on it, but like all things Magpul, they glob that stuff on the screw. Half way into the trigger guard, it began to bind. Using my quality Wiha bits and hex keys didn't matter. The tiny 1/16" hex head stripped out. Used a #1 Speedout bit to remove it and replace with a new #5-40 x 5/16" set screw without threadlocker since the trigger guard is polymer. I have a pack of button head screws on the way to replace these junk set screws. So for anyone that thinks AR's are like snapping LEGO bricks together, you haven't put enough rifles together to encounter this BS.