Yes, that is what we call a "Blunderbuss."
And that is pretty much what I was thinking when I posted the singleshot primative weapon issued to your masses.
Now, make it a large bore like the above, but not funneled. Add hammer that fires on a primer like the caplock rifles/muskets. These with todays knowledge are pretty easy, heck, they are common in childrens cap pistols so no big deal, and then mount a spike for thrusting and an axe for causing even more chaos when it comes to close quarters. Talk about the ultimate primative close quarters weapon
