Used to do die casting ….
yep ! In small amounts its a pain … Aluminum Melting temps and everything make it a whole new ball game to casting bullets …
Though we used electric furnaces that held Gallons of molten aluminum … Some perhaps 40 gallons or more
The smaller ones might have been 10 to 20 gallons ( long time ago )
No problems with cooling , unless your talking about how long it took to cool …
The furnaces ( melting pots ) needed to be serviced from time to time , and it took an entire day to empty and cool …
And then there is the casting procedure / process that needs to be right or you end up with garbage …
I would seek out a casting company / business that does small jobs ( often sand casting ) … and see if they would not part with some supplies …
I even recall there were some community type work shops here and there that did casting on a small scale … ( Like bronze ) ( U know , artists )
Hell when I was turning I just called Hawker pacific / commonwealth aircraft / and asked them for some hard to get materials …
They asked me what I wanted them for and I told them I needed materials for model airplane engines … They said sure , no problem !
Nothing politically incorrect or sensitive about model airplane engines …
Sourcing stuff can be a pain … I don’t know what Bar costs these days ?
But sometimes you just got to ask whats in the off-cuts bin … Some companies will allow you to raid the rubbish bin , others want $$ just for talking to you …
Machining stuff can be fun and frustrating …