new at this rifle

[jsta5.56shooter]

hello folks,just tryin to figure out how to ID my ar15 a2 upper receiver.
any help is appreciated.
jsta.

[5POINT56]

Here's a link to some info on uppers.............

http://www.biggerhammer.net/ar15/uppers/

Tell us what all the markings on your upper are based on the diagrams in the link...in addition to barrel markings.