Most people slaughter at 5 pounds and in commercial rabbitries that is usually at 8 to 10 weeks.
I have found that rabbits over 16 weeks have a stronger flavor, more 'gamey', probably due to their hormones starting to kick in and the pelt is better attached and harder to remove so I butcher before 16 weeks regardles of how much they weigh.
I am the weird one here cause I don't find any difference in taste at whatever age I process. I do agree the pelts are a bit more difficult to remove when the rabbit is older but not awful.
Thank you so much everyone you have been a great help I probably will do them about 10 weeks. i really hope me and my house hold will like rabbit meat!