Rob,

I would suggest you start with something like RWS Hobby (7.1 gr.) or RWS Meisterkugeln Pistol (6.97 gr.).

I generally use RWS R10 Pistol (6.99 gr.) in my HW30S for the MPL.

I have not found the HW30S to be 'pellet fussy'.

Have fun

Best regards

Russ