Had a couple of them. Baikal, TOZ66, 3", and after sixty years of shotgunning this the first time I have ever heard that there may be different chambers for roll or fold crimp. I think it is the product of an overactive imagination.
Shells are a finite length when fired and chambers are cut for specific lengths. The forcing cone begins at the end of the fired, opened case.
There were many shotguns made in years past with 2 1/2, 2 9/16, and other length chambers.
My Baikals had 30" full and follow and the other was a 20" IC, M. Both were hammer guns and had Greener crossbones. They did have a knurl design at the 3" position ahead of the breech.
None were made or imported during roll crimp days.
