I proceeded building the horizontal stabilizer, took the skins off again to debur and drill holes that was missed the first time. I double checked all the edges, as well as all the screw holes, and confirm that all was deburred. I riveted one side, making sure to put all the rivets in correct places, no mistakes was made. The AAAPQ 41 rivet mandrel is sticking out on all the rivets. This is the correct rivet confirmed