A Sci-fi explorer skin concept for my previous CCMBR: Anti Tank Rifle. Concept for skin is a retro/steampunk railgun with some influence from Sir Edmund Percival Hillary (first man to climb Mount Everest), mountaineering and old navigational equipment.
The barrel is a sealed chamber with channels pumping liquid nitrogen to super cool the magnetic drives inside, giving off a white haze once fired. A removable power cell is housed inside the stock but is often left in and charged through power connectors along the side of the rifle. Thermal optic to round things off with a slight elevation to overcome the haze from the barrel.