Here is a simple .22 revolver project built by a reader from absolute scratch using basic tools while following the plans here. For a gun built at home from scrap steel it isn’t far off from looking like a commercially produced handgun, far flung from typical makeshift contraptions though still within the skill range of the average layman with nothing more fancy than a drill and a stick welder
Materials used during construction included steel plate and bar stock which were welded together to form the frame while parts such as the trigger and hammer were cut from 0.3″ steel plate.
“I found the trigger and hammer tricky with the revolver, you need to leave an extra half mill of material and finish them slowly. The best way to make the cylinders is to make the indexing marks on them, finish the little spring detent part then drill the dimples for the cylinder indexing through the detent hole, then drill down through the barrel (using it as a guide) into the cylinder, only need to go a few millimeters into it to get the holes started. Then when all 5 are done take it out and finish on a drill press, then flip around and do the chambers. It ensures perfect alignment. Fun little gun and feels nice in the hand.”
Demonstrating that a viable firearm can be produced without relying on any firearm components, a cap & ball version was also made which uses plastic toy caps combined with homemade gunpowder and a .25 lead bullet. This version apparently shot accurately despite being smoothbore.