Pumping to empty

I want to start pumping after feeding to increase my supply. The most I've collected while pumping (even when I pump in place of feeding) is 1 oz. I'm using the spectra 2. I collect more with haakaa's, while feeding.

Is it time to try a different pump? I have no luck with hand pumps either. Any tips or recommendations would be appreciated!

Anyone else collect more with a haakaa or something like it?