Harlan, yes the research and Learning. That's the fun of the collecting.
Just a note, almost all of the 1917 Enfield launchers made were either shipped to other nations along with the Enfield Riflesthe US provided them under the lend least provisions or post war re-armament and those launchers remaining in the US, were converted to 1903 launchers. So they are extremely rare.
Another launcher I have and my only non US launcher, is a Japanesetype 100 grenade launcher. This launcher is unusual in that it uses the gases tapped off live round to fire the grenade unlike most launchers that use a blank type cartridge, Ray
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