The raw materials for handguns - chrome molybdenum steel. (alloy made by adding a little chrome and molybdenum to iron. High strength and also high temperature resistance. It is also used in bicycle frames and aircraft.)
And likewise, stainless steel. (steel containing no less than 10.5% chrome in iron. Having workability and endurance, it was called "stainless" due to corrosion resistance and is widely used)
Production of steels that can be adjusted for strength, corrosion resistance, and endurance was now possible.
If I were to produce modern weapons—handguns, I wouldn't plan on using black powder, but instead something stronger like smokeless gunpowder.
Therefore the strength of ordinary steel is not enough.
21st century gun barrels are almost entirely made of chrome molybdenum steel or stainless steel.
For that reason I have to build a "converter".