Supposedly the Irish Royal Ulster Rifles regiment, WWI.
“Supposedly the Irish Royal Ulster Rifles regiment, WWI.”
Some 7,010 soldiers from the regiment were killed in action during the First World War.
Looks like the saw quite a few trenches, including the Battle of the Somme.
It might also be a grenade launcher, or a combo flare/grenade launcher.
The mounting bracket might allow you to set a rig ahead of time, for an accurate first shot on a certain position - like dropping one right into your old primary position, if you have to fall back to your secondary (knowing the enemy will have to take cover there from direct fire).