Ahaha, thank you. :3
5mm is about 6ga, if I'm correct, and you should start with 1mm/14ga.
Plus when stretching from sizes like 8 to 6,and 2 to 0 you should use PTFE tape (I found some at K-Mart for like less than five bucks, adn I'm sure you could find some at Lowe's or whatnot) because...