So I took my new AR to the range today to put a few rounds through her, and after about 20 or 30 rounds it failed to fire. Not because of brass though, the trigger simply would not depress. I attempted to put it on safe in order to inspect it, and the safety wouldn't budge. I removed cleared it, removed the magazine, and broke it down to look at it and noticed nothing strange. The bolt seemed and functioned fine, the chamber looked okay, and lower receiver looked fine. I didn't notice anything out of the ordinary. Am I missing something or am I going nuts?