Star Trek - Lost Souls [Cortex +]
Mina Firearms Technology
The Mina firearms technology is based around a medium grade gun powder technology mixed with a piezoelectric firing mechanism. Rifles tend to be breach loading, the mechanism like this one is simple to operate and fairly reliable.
Pistols come in single-action for the most part.
And what amounts to about .40 caliber is the norm for both rifles and pistols with some exceptions.
The Combine Arms Group (CAG) issue their officers double action revolvers, but these are still breach loading and generally run a slightly lower caliber and powder mix to reduce recoil for rapid fire. such as these .30 caliber double action CAG pistols.
The Regulators use a hybrid double-rifle weapon which is a high caliber rifle (.50 caliber) for long distance shooting and a shot-gun load for close range.
Artillery advanced during the last Civil War and the height of this is the Railway Guns that were used by both sides for heavy bombardment.
These guns were deployed on the rail lines and used on targets up to fifty kilometers away.