I show the 3 main diameters of Vent Tubes for British artillery guns.
1" Australian made is 127mm long with a 33.5mm rim and 25.4mm body.
0.5" is 56mm long and 17.4mm rim. Tapers from 12.7-13.3mm.
0.4" is 55.7mm long and 14.3mm rim. Tapers from 10.0-9.5mm.
These three Vent Tubes are not often photographed together to compare sizes.
1" Australian made is 127mm long with a 33.5mm rim and 25.4mm body.
0.5" is 56mm long and 17.4mm rim. Tapers from 12.7-13.3mm.
0.4" is 55.7mm long and 14.3mm rim. Tapers from 10.0-9.5mm.
These three Vent Tubes are not often photographed together to compare sizes.