If I recall correctly, the Bessemer process for making large quantities of inexpensive steel, was patented around 1856. I have never quite understood why Colt and Smith & Wesson, among others, were still using iron in their revolvers almost 20 years later. Perhaps it took a while to get from the patent to the actual production of inexpensive steel.
I use a Lyman Black Powder Measure.
There is a pretty good photo of it here on this Cabelas page:
https://www.cabelas.com/shop/en/lyman-no-55-classic-black-powder-measure
The body of the device is iron, the rotors that meter out the powder are brass, and the hopper is spun aluminum. Because the rotors are brass they are non-sparking.
This powder measure is basically the same as the classic Lyman #55 Powder Measure, except for the aluminum hopper. The hopper is much larger than the plastic hoppers on the Smokeless powder measures and can hold a lot of powder, because Black Powder cartridges need a lot of powder.
I buy old Lyman Smokeless powder measures when I find them cheap at the white elephant table at gun shows. Notice they have a plastic hopper.
I set each rotor (the rotating part that meters out the powder) for a specific powder charge. There are two or three (I forget now) slides built into each rotor and I set them for the specific powder charge I want.
I set up each rotor for a specific charge of Black Powder that I use in specific cartridges, then I label them.
With each rotor set for a specific powder charge, I only have to remove one screw to change rotors for different cartridges.
This is a view down inside the iron body of the powder measure with the aluminum hopper removed. It shows one of the rotors installed.
The linkage that operates the standard Smokeless powder measure on my Hornady Lock and Load AP progressive press does not operate the Lyman powder measure. I have to remember to rotate the handle to throw a powder charge for each cartridge.
Here is a photo of a batch of Black Powder 44-40 ammo being cranked out on my Hornady press. The powder measure is out of view in this photo.
Here is a view of my loading bench with the Black Powder measure installed on the Hornady press.