Some lunatic decided to crossbreed a shotgun and a mini-vulcan and created one of the most ludicrous ammo hungry conventional weapons of all time.
Everyone expects the power armor trooper and his trusty combat rifle, assault rifle, storm-bolter, etc.
The ultra-rare and ultimate firearms favored by gun adepts, assassins, and snipers.
Squirt guns are typically non-lethal weapons used to deliver debilitating chemical agents.
30 pistols, rifles, and assault weapons
The commericaly available firearms of the Cosmic Era
The basics of magnetic weaponry in the Cosmic Era
Drawn from the rather generic Gunslinger Adept from Shadowrun, but influenced very strongly by the 2002 film Equilibrium and the 2008 Wanted.
When running a new party, get around the question of plot density by having the first discovery to be a deck of fate, or whatever you call it. If you use a real deck, you should definitely stack it to have the desired outcome, which is to curse the party to attract weird things to happen and involve them. This should not be told to the players at the time, so that they won't just up and try to get themselves 'decursed'. Though quite why they would want to is beyond me.