Got a Real-World Weapon, Armor or Tactics Question? Mk. XXIV

[fusilier]

But it would help to know - is it difficult for people using early firearms to produce gunpowder in sufficient quantities?
What is a good tech level for a firearm that did not do much to overshadow relatively low-tech armors and weapons? Some kind of firearm you might see alongside knights in mail wielding spears and shields?

In Europe gunpowder was expensive and somewhat difficult to produce when first introduced. There the problem seems to have been saltpeter, which, once the natural sources had been exhausted, had to be produced. It took some time to figure out how to produce it consistently. As a result gunpowder was expensive when initially introduced, but the price dropped over the course of the 15th century.

As for firearms -- handgonnes and early arquebuses, are probably the most likely, although, historically, they overlapped more with plate armor.