In Robert Groden’s video of Alyea’s film he states that the lifting of the rifle by Lt. Day was staged for the camera.
Groden:
“Billy Lovelady, a depository employee, was present when this film was shot. He said this finding of the rifle was staged, that it had already been found and replaced, and that this scene was replayed for the camera.”
The crime scene photos by Day and Studebaker appear to show the in-situ rifle lying vertically scope up.
Alyea’s film appears to me showing the rifle lying flat on its right side as he lifts straight up by the strap.
Groden’s/Lovelady’s scenario does not conflict with Day’s testimony he picked up the rifle by the “wooden stock” and gave to Fritz, who ejected the un-fired round, leaving the bolt handle in its upright/unlatched position for Alyea’s film.