Goggles On!
Most military action is air-to-air. Or rather giant steam/plasma-punk dirigible to giant steam/plasma-punk dirigible. They have deflection shields which can stop small firearms coming from outside the dirigible. This is why electro-mortars and scrap cannons are needed for one ship to shoot another.
When it comes to boarding parties however handguns are a liability. The ships spend a lot of time above the weather where the air is thin. Shooting bullets willy-nilly will can either:
(a) puncture your airship's swim bladders and make it fall from the sky. Bad.
(b) make holes in your airship and let the space air in and suffocate your crew. Also bad.
This is why boarding parties use sillier more short range weapons like glue shooters and net cannons and chair legs.