C360 Brass (Free Cutting/Machining) is the benchmark for ease of machining...

https://www.metalsupermarkets.co.uk/...ass/brass-360/

It's a joy to use - CZ120, CZ121 etc. readily available, but like you say, not cheap...

If I were you, I'd stick with getting the right parameter sussed out for ali - you may as well. I've still got my beginner melty bits in a box of scrap somewhere, you need to break a few eggs to make that omelette. Get crackin'.

Wal.