Turning issues

[Muzzer]

That's chatter or judder. The usual cure is to increase or decrease the speed and / or feed until it stops. Often people reduce the feed or speed but you may find that increasing them is a actually better solution.

As you are machining brass, you may need to use tools with little or no top rake. In a twist drill this would result in flutes with no twist and on a lathe tool, the top of the cutting edge would be on the same plane as the centre line. Normal angles intended for cutting steel or aluminium would be 5-15 degrees but when these are used on brass, they want to dig in. If you want an exciting time, try drilling brass with a sharp steel cutting drill!

They call it "face rake" here but either way, it should be a small angle or zero.
https://en.wikipedia.org/wiki/Rake_a...l_Cut_diag.svg