Del-ton upper - Del-Ton Pre-Ban Government Profile Flat Top Barrel Assembly

Mounted this upper to an A2/A4 style lower with full buttstock and A2 pistol grip. It has the look of an M16 A3/A4 rifle. I like a 20" barrel, especially one with a 1/9 twist.Mounted a carry handle then calibrated the elevation drum by loosening the set screw and turned the top part of the drum six clicks past 6/3 (counter clockwise) then reset the set screw. I turned the elevation drum 2 clicks past 6/3 to the z setting and proceeded to sight in at 25 yards with the front sight and the rear windage knob.It will now hit POA POI with the windage knob set 6 clicks past 6\3 at 100 yds. And at 50 yds with knob dialed 4 clicks past 6/3. And all the way to 600yds.throughout it's various correct yardage settings.Used with XM193 55grn. 5.56 ammo.I did change out the big oval handguards to the correct A2 style.