75mm unmarked fibre tube ID needed.

[917601]

I have this black fibre tube that I have an M18 75mm case sitting in. None of my WW2 75mm complete rounds with the APC or HE fitted into the M18 case will fit into it properly. However, the closet fit is an M5 pack howitzer case with the M48 fitted.
What round does this fibre tube belong to? The end caps are unmarked. The tube is 27 inches long with the cap on assembled. The cap is 6 inches long. The tube w/o cap is 25" long. I am sure it is for a 75mm as the M18 fits well diameter wise.All comments welcomed.

 

[kiwieod]

it may be missing some of the internal packing like cardboard washers and tube which fit around the fuze to support it
this may explain why the rounds don't fit properly

 

[917601]

it may be missing some of the internal packing like cardboard washers and tube which fit around the fuze to support it
this may explain why the rounds don't fit properly

Understand, however, the assembled 75mm AP and HE rounds I have are to long. The 75mm that fits it is the M5 pack howitzer case with the M48 HE projectile, fits lengthwise with about a 3/4" space past the fuze. Anyone have an example of a packaged 75H round?