Not sure of just the upper, but Midway shows shipping weight of 20” upper just about 7 pounds with standard barrel and plastic handguards.
A complete A2 is a pretty standard set up. If an HBAR with an A2 stock and carry handle you will find rifles around 8.5 pounds. If you get a gov’t profile A3 barrel you can shave about 12 - 16 ounces off that. Substitute an M4 telescoping stock setup, properly buffed and sprung and you can save about 8 ounces, IIRC.