I've got a similar problem OP, my DS(8 weeks) was born 9lbs and is now 14lbs 3oz. He has not stopped stuffing his chubby little face. Midwives and HV said not a problem, that I am doing right by feeding on demand and I know EXACTLY what the back to back feeds are like. When he screams after finishing a bottle, being burped, changed, cuddled, bounced etc you think surely to God he can't be hungry but yup ... he is. HV seems to think it will pass, so all I can suggest is wait and see? I know how bloody expensive it can be too
Thanks admiral, that has made me feel so much better!
I think (touch wood) we have calmed down a little bit, we are still feeding mostly 2-3 hours but there is a couple of times a day it will stretch out to nearer the four. We do feed constantly at night though. Seems to be routine now to down 3 bottles between 8 and midnight.