03-01-2019, 01:12 PM
Diecast zinc has one advantage. It's the only metal that doesn't shrink as it goes from liquid to solid. So no post-molding machining required. It's great for complicated shapes like carburetor bodies and gas control valves. Manufacturers love it.
BUT. The advantages end at the manufacturer, it's lousy for the consumer. Heavier than iron, softer and weaker, the same iron part made in zinc has to be thicker for strength so much heavier. Galls and scores if not completely clean and lubricated. Readily corrodes. Deforms under pressure.
I can see some disadvantages to "annealed polymer" gun parts (some advantages as well), but diecast zinc? A gun is a tool your life depends on. Why don't you get a zinc Crescent wrench, see how that goes?