Do you sit on your genitals?
(More seriously, I presume shadowsteeds come with shadow saddles. Also: Pants exist.)
Seriously speaking, people fear magic and will strongly prefer not to use things which are blatantly magical and unnatural in nature. Shadowsteeds are blatantly magical and unnatural, which means that the riders are likely to blame the steed for any bout of impotence, constipation or other general issues.
I believe Mathilde has a pistol, not a handgun, and although, yes a crossbow or rifle would outrange either, the only weapon I'm aware of called a rifle, is the Hochland long rifle. The analogue of a regular rifle is the handgun, which is outranged by crossbows, at least on the tabletop.
Important clarification: Rifling is NOT a late era innovation. People knew spinning projectiles flew straighter and further, and fletched arrows to induce spin in flight for a long time BEFORE guns were a thing, and it was something that was done to guns and cannon for a long time before it became widespread.
The core problem was twofold:
-Metallurgy. Rifling was a structural weakness in the gun/cannon, which is important when barrel strength could not consistently contain the explosion as it is. Dwarfs do not have this problem, their metallurgy is literally inhuman.
-Cost. Rifling prior to the development of machine tools(especially the ultra hard tool steels), involved hard, detail work by a specialized artisan, which given that guns and cannon were considered crude weapons early on, meant that few artisans of the necessary skill were making guns because there wasn't anyone paying enough to be worth the trouble.
Basically, the dwarfs have everything they need to make an effective rifled longarm, and know how to do so but their best craftsmen are staunch traditionalists who refuse to make guns and theres not really a lot of buyers beyond eccentric Grey Wizards, Witch Hunters and noblemen who fancy themselves to be fine gunners.
The question isn't whether a gun is possible or not. The question is whether its a good use of actions and resources for the gain. Our equipment configuation is pretty tight too(BoneyM had indicated that equipment bulk DOES matter):
-Back(shoulder to thigh) - Greatsword.
-Hip - Pistol
We could fit another item of maybe 3-4 ft long in a hip sheath without encumbrance, our pockets should be filled with gun ammunition already.
The kind of powerful crossbow you'd use for sniping at a long distance should be a slung on your back due to their size, and would require an additional quiver to carry bolts for it.
Alternatively we leave the long range sniping to the dwarf rangers, pick up Shadow Knives and do what we do best.
Didn't Mathilde basically budget 5 years for the Expedition?
Sure things are sort of winding down now because a large part of Karak Eight Peaks has been recovered after significant battles and even Dawi need some rest but there's no reason to not try to at least clear out the greenskins and trolls from the other peaks in a couple years.
Odds are good that we won't be seeing this sort of large push again until enemy leadership makes themselves known for a critical clash. Its just so much more effective, given a stable base camp to work from, to raid with dwarf gloryseekers over an extended period to bleed enemy numbers before taking Karags room by room, fortifying as they advance.
@Alectai while I like the tower at the top idea as doable, I really don't think you want the vault at the top of it. That's just asking for some flyer or dragon ogre to climb the mountain from the outside, punch in, and run away with your stuff. The dwaraves make vaults deep underground, and they are very, very, good at it. I'd much rather have a place in their vaults, then try and make something new. We already know those things can stand up to centuries of abuse.
For the magical stuff and the secret stuff we don't want the vault separate from our working area.
That said, we don't exactly need a LARGE vault either, this is mainly for books and reagents. Concealment may be better than depth.
Also keep in mind that the Karag is built with anti-air artillery in mind and it'd either be an overwhelmingly powerful enemy which knows exactly what its looking for...or it's not going to do this thing which is going to hurt a lot for no reliable gain?
Yeah, just recall how much of a HELL we had building a functioning spy network from scratch.
Being able to inherit a network is an enormous boon.
When we started in Stirland the Stirland spy network was one wizard in the basement.