Where can i get one?????? I want one to check brass with.

Go to a heat treat shop. They should let you use theirs.

Don

Forgive me if you know this, and it is admittedly a good while since I used one, but you do need a good-sized test piece for testing in your ordinary Brinnell machine. It depends how hard the material is (the harder the test piece the thinner/smaller the test piece you can get away with) but for typical cartridge brass you're probably going to need a test piece a couple of inches thick and a bit more across to get meaningful results. If that is what you have in mind though, go for it, but there are other methods better suited for thinner sections.

Rockwell testing machines would have to be pretty widespread, as they are found in many factories, mechanics' and engineering shops, and you'd only need a testpiece a few mm thick. For even thinner sections you want a Vickers or Vickers Microhardness set up - the latter will allow you to test hardness gradient across the prepared cross section of a cartridge case, but you'd need to look in a metallurgical lab to find one.

BTW there are tables to compare the hardness number derived by each method (though the correlation is not quite exact, due to differences in the way each test actually derives a number for hardness).

HTH