Please help! Cant figure out baby’s eating What are we doing wrong?

My baby just turned 6 months and seems to have a growing appetite. So we went from 4 oz to 6 oz but he still acts hungry so we try 8. Im confused because he STILL acts hungry - making sucking motions and pulling bottle to his mouth. But then also shows signs that we may be over feeding him. He spits up a decent amount after every bottle, some are pretty bad - he wasn’t doing that when he had 4 oz. We also overfed him for a brief time when he was 2-3 months and he shows a lot of the same signs. The hunger cues are what’s throwing me off tho. So if he eats 6 oz and still acts hungry, does this mean he’s actually still hungry and we should try baby foods/cereals? Or is he just processing the food?