[quote=@ClocktowerEchos]
[@Irredeemable] Given what I'm presuming is the current state of technology relating to gunpowder, I doubt you want to actually be using mortars unless you want to go through artillery crew on a daily basis.

Early mortars were inefficient at the best of times and extremely dangerous at the worse. The fact that the GM said most gunpowder is old, wet and in otherwise not top quality would suggest that trying to do use mortars would be exceedingly hazardous to one's health and the health of everyone in the nearby area. You're honestly better off just have a catapult or trebuchet with firebombs since at least operating a catapult won't result in the machine itself exploding half the time.
[/quote]

You can have Mortars, but as Clock said, you have to be aware, that your Gunpowder is old, wet and horribly outdated! Sure, a rats life is cheap, and the effect of explosives are Extreamly effective against Skulkers and other Bigger Beasts, yet the trade off is a little understood technology! As such, your gunpowder weaponry would be small and limited, until you can find a reliable source of stable, dry gunpowder.

Still, not gonna ban Mortars from your Clan, even they would be the most primitive form of it! Yet, Lost limbs, should be quite a common sight among their weapon teams. They are not limited by the Technology or understanding, but rather by the powder they work with, which is old, damp blackpowder from Fireworks