30618 CM-8EA** $.60 4.180" 1.685" 1.785" 0.021" .368 6
30616 PST-65R $.55 5" 1.595" 1.641" 0.023" .368 7

http://www.ninfinger.org/rockets/cu...no_diagram.html

http://www.oldrocketforum.com/print...54&page=2&pp=10

http://www.oldrocketforum.com/print...54&page=4&pp=10

See Tubes:

http://www.oldrocketplans.com/centu...F-10Hustler.pdf

ID 1.75
OD 1.84

U.S. Rockets 54mm casting tube is 1.80 x 1.86. Close.

http://www.rocketmotorparts.com/54m...09_7781922.aspx