I would never run that Makita at full speed for anything you do on your machine.
I'd try about .005-.008 depth, feedrate around 10ipm, and maybe 15,000 rpm.
I've never cut brass, but have cut aluminum with a similar size bit.
Use a little WD40. Some brass will cut better than others, depending on the type. With a little WD40, it shouldn't be a problem.