Cracked upper? Replace or shoot and forget?
It looks like a scratch, but may be a crack. Its an Armalite, and I'm not the original owner, so there's no warranty. Given its location, it may not be a safety issue, but then again, I'm not really an AR guy and would not want to make that call without some expert advice.
Tech support at Armalite couldn't tell without manual inspection, but thought it looked like a manufacturing artifact. My armorer will inspect it later this week and tell what he thinks.
Q: break it up for parts and demil the upper, replace the upper with something like a BCM blem flattop, or shoot it and forget about it?
http://i33.photobucket.com/albums/d8...Armalitex1.jpg