Appears to me you're one decimal place off on the 32's. Should be .215, or two hundred and fifteen thousandths, not .0215, or twenty one and a half thousandths. The 36's seem more in line with reality. Taking one-half of those numbers would give you a calculated wall thickness near the end of the cone of about .108 or one hundred and eight thousandths. That is not an unreasonable thickness in my experience, tapering to .060 at 6 inches and .045 at 9. Others probably have other pet numbers, but those are the ones I'm most comfortable with as minimums. I will confess I have shot one 16 gauge quite a bit that mics at .072/.085 MWT at the end of the factory 2 1/2 inch chambers, but it has Vulcan steel barrels and I only shoot RST low pressure loads in it. You've got to decide for yourself what your minimums are.
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