Abstract: An accessory mounting attachment for repeatable precise alignment on a rifle has a mounting section with a top rail. The mounting section has a forward portion with a rear sight leg configured for a pivotable mounting to a rear sight base on the rifle, and a rearward portion with a lock down assembly configured to fix the mounting section to a connecting lug at a rear of a receiver of the rifle. The lock down assembly includes an eccentric element, a lug latching frame, and a coupling element connecting the two. Rotation of the eccentric element by a lever section causes the lug latching frame to move vertically and engage/latch with the connecting lug, so that the accessory mounting attachment is consistently and securely fixed in a same position relative to a barrel of the rifle, which keeps a sighting device attached to the top rail zeroed to the rifle.