Simple hanger to hang rifle with A2 type muzzle device (44 mm long, 22 mm diameter and 19 mm wide flats for wrench).

Curved top inside corners to prevent contact between the bolts and muzzle device

2 holes for M4 screws to attach ~25 mm diameter magnets (1x25 mm is a bit to weak, one 25 and one 19 mm, as in the pics, works fine for rifle with red dot and magnifier) and stick it to the gun safe ceiling.

Operation: