I’ve seen designs that only have one metal component a nail. There’s several 22lr designs that use entirely printed barrels. They won’t last as long and need to be designed around the material qualities, but do function safely.
There’s also a few designs that can be made with parts from hardware stores without any particularly expensive machinery (like mills or lathes). People can even rifle barrels at home through electro-chemical machining which isn’t as complicated as it sounds.
I’ve seen designs that only have one metal component a nail. There’s several 22lr designs that use entirely printed barrels. They won’t last as long and need to be designed around the material qualities, but do function safely.
There’s also a few designs that can be made with parts from hardware stores without any particularly expensive machinery (like mills or lathes). People can even rifle barrels at home through electro-chemical machining which isn’t as complicated as it sounds.