>>95866989
I've always leaned toward 17th century, since I just can't let go of dudes in armor. Although in reality I've never known where exactly to place my own setting given the technology. The most common form of firearm uses an action with a hammer striking an internal flame crystal to produce the spark. This makes the mechanics of the gun slightly simpler than a flintlock, but the quality of the crystal introduces a whole other variable to the gun. The crystals aren't terribly expensive on the whole, but a really super high quality, reliable, long-lasting crystal might be as expensive as the rest of the gun while a particularly cheap crystal may be prone to cracking/misfiring just from dropping the gun and will wear out relatively fast. All that in mind, I've never been entirely sure how that would place it compared to flintlocks or matchlocks and the greater implications thereof.
Another thing I've never been too sure of is bayonets. I really like the idea of having the option for bayonet fighting, but barrel plug style bayonets are always kinda awkward and introducing socket bayonets is basically the transition point beyond the era I otherwise want to be in.