>>64149310
That reminds me of how some old 22s (~100+ y/o + especially the cheap ones) actually had brass barrels. Yes, honest to god brass. I believe the Hamiltons were mostly brass barreled; most had an iron shroud tube over them much like a Red Ryder, which would be odd but this company lead to the eventual creation of Daisy believe it or not.
https://tincanbandit.blogspot.com/2019/08/firearm-factory-of-month-hamilton-rifle.html
They made pump and single shot, all rifled. Apparently not that durable. Not sure about ZAMAK but it might be okay with loads of rather low pressure and like, soft lead cast only maybe. I'm no metallurgist nor engineer though so while it certainly seems possible I can't say whether it would last or be safe. God help you when that thing gets some age, too, as bad ("contaminated") blends of ZAMAK can develop something similar to tin pest where the whole thing starts to crumble, almost like you put gallium on aluminum. It's a huge problem for old toy collectors and totally up to luck whether that batch of material was good or not.

PS: Hamilton rifles were often given away via random chance. Some models of single shot were placed into large sacks of dry feed at random. Some lucky farmers would cut open a sack of feed only to find a brand new Hamilton single shot lol. I believe the pump models were also given away as a prize for getting x number of people to sign up for subscriptions to a magazine or newspaper. Boys would essentially go door to door trying to get enough subscriptions to get a rifle in the mail. As I read they supposedly weren't built super well but weren't junk, but the easy-to-screw-up brass barrel and overall cost cutting measures meant a lot of them got used around the farm hard and that means a lot of them went into the farm trash pile. They're uncommon but I've run across several for anywhere from $800 (immaculate condition TBF) to $125 for a pair (one functional, one beater easy to restore).