Sorry, wish I could help you but I just never weigh my snakes unless for specific reasons (like the need to dose medication, for example).
It's more of a "thing" for BP-keepers anyway (of which I currently am not), since they tend to fast & scare their owners the most.
I think there's quite a bit of variation anyway...they don't all start off as good feeders before you get them, or worse, they might have been
"maintenance-fed".