You're using fire vs fire. You need ice. Freeze them with the freeze bombs then use arrows on the weak points, it doubles the damage when it's frozen. After about 4 arrows they then explode and this causes further damage. Rinse repeatRight but when I fought my first bellowback my fire arrows were not effective at all, every time I hit the damn thing the fire gauge on the machine moves by a really really small amount and then I have to roll to dodge the fire spit attack. By the time I could aim again the fire gauge had expired and I'd have to build it up again. Not that I was ever able to get it past 25% in the first place
I have the blue hunter bow rn, is that too low?