As for the cosmoline, it will work fine in a #" barrel glock, but try filling the barrel of a gas-operated high powered AR15....no good.
Anyways leave the kid alone, hes fine, his rifle is fine and no body was hurt. He wont do it again. I PERSONALLY dont see how you didnt take it apart .037 seconds from walking in the door...I did
Anyways
There weird when there new...new gas rings and everything. Note:If you dissasembled it the bolt is hard to take out/put into the carrier...but if you do it after a hundred or so shots are fired it pops in and out of the carrier with a nipping action. Funny.
Clean em, use em...and abuse em. Its a rifle used by elite forces worldwide...once the factory goo is taken out it will be hard to get it to malfunction again.
Cheers on your first ar15! I remember getting mine....I remember the calll....Hello...Mr.Brandt....yes your AR15 came in today bud
LOL!