Strength of materials discussion.
Once you build to requirement, not rumor or hype or myth, you build a whole bunch lighter.
A USR typical kit is 0.040" wall tube and 2.25" diameter or 4" diameter and good to GHIJ power.
Above that an 050 wall tube is good to anything but silly thrust or greatly increased power motors.
But then do you really need fiberglass or carbon fiber? Nope. We have 080 wall paper tubes which
are 50% more cost than 050 wall tubes that have never had their power or thrust limit exceeded.
Above that isn't it better to just put your steel fin can on your aluminum motor casing anyway?
You know, since it takes two guys, or equipment, to load the propellant grain(s) anyway?
Be real, not silly.
Marketing by some other companies is one thing, but overkill is a term for a reason.
3 inch ID 080 wall tube proven beyond L3000.
3.9 inch ID 040 wall and 2.6 inch ID 050 wall tube good to
J+ when used on conventional configuration rockets.
Technically each particular tube has a frontal force or
altitude adjusted speed limit, not a power or thrust limit.
Drake "Doc" Damerau, is an engineer who works for General Dynamics
at the Scranton Army Ammunition Plant in Scranton, Pennsylvania. As
the Chief Metallurgist, and the Laboratory Director, Doc specializes
in failure analysis. That equipment is perfect for testing the
strength of new tubing.