Today I found an Aluminium tube, I found it in an area of high military presence which I highly suspect it to be military.
It measures exactly on the dot 30 inches long, 19mm wide (20mm wide at the 'eyelet' end) Bore 8.16mm diameter. 'Eyelet' slot is exactly 50mm long and exactly 10mm wide. No markings anywhere. Seems quite precisely made!
There is a hole in the base of the iron end, but it doesn't want to upload that pic, for some reason!




Many thanks

Simon