The gunpowder weapons in use are the same as the Renaissance weapons on pg. Those using gunpowder and those powered by aberrant technology.
There are two types of firearms in Exploration Age. Below is an excerpt from the upcoming Exploration Age Campaign Guide which gives the firearm and bomb rules for the setting. Of course their counterparts, aberrant firearms and bombs will also be available as well. The Renaissance items from that book are available for PCs and NPCs alike in Exploration Age.
A lot of those rules are being thrown out since the Dungeon Master’s Guide presented official rules for gunpowder weapons and bombs. Some of my first popular posts were on firearms and explosives.