I have heard rumors of 475 linebaughs having been built by boring out six shot ruger cylinders. If the six shot 45 colt cylinders could take those overloads, then the rumors of the six shooter 475's are plausible.
I've seen and held one six shot 475 linebaugh gun and it had an oversized cylinder. At that, its maker didn't feel that it should really be leaned on. The cylinder on that gun was even bigger that the six shot 480 Ruger cylinder in the redhawk, which Ruger didn't feel was strong enough until they went to a different steel.
