Tonality

I think milling would be the best option (solid, secure and good transfer of energy). You could try buying an 'end mill' bit and throwing it on your drill press. you don't need high rpm to cut brass. you would also need a milling vice. between the bit and the vice you're looking at around $100. Your chuck has to have NO wobbles for an accurate cut. You might think about also getting a machinist dial indicator. They are good for all sorts of tool calibrations.