Boresight Telescope Mark VIII Mod 6 BOAC According to the RAAF 346

According to the RAAF 346 Types and Locations of Instruments in RAAF dated 1945

25 inches diameter by 5 inches deep

probably for a weight balancing system prior to this being an automatic process

part number 1559-010130

and ~16 inches by 8 inches x 1/4 inch thick when opened

Boresight Telescope Mark VIII Mod 6 BOAC According to the RAAF 346Designed for naval ordnance, this Boresight Telescope, made by Spencer Lens Co., was used to align the bore of a naval gun to its distally mounted gunsight along the specified firing range. The telescope was positioned within the bore of the gun during the sighting procedure, to align the line of firing with the line of the gunsight, intersecting them along the specified firing range. Used for sighting 3" 50 guns. The case measures 12. 5 inches long,