Should I upgrade this guy's feeder size? He lost about ten grams between two feedings, from 280 to 269. I was given the possibility that he took a huge poo in between, but I generally will only weigh him after he's pooped for the last meal he had.
He gets an adult mouse every 5 days, and is VERY enthusiastic in between feedings, searching around everywhere, surfing the glass, rustling about at night in between or during the day even after I would remove him to check for/clean up a poop he would be restless for a while after. I know this is likely normal for a growing BP.
The pet store near me goes from adult mice to small rats, and I'm wondering if the feeder is too big for him at the moment. If so, should I order some smaller rats online? Or just stick to the current mice? Below is an image of a small rat and the BP's widest body area along with weights.

BP weight: 296g
Rat weight: 50g
Current feeder mouse weight: 23g