You must be a complete idiot. I showed that the Marine Corps ordered over 20,000 shotguns with 14" barrels. But the argument never was about 1934 NFA regulations. So your contribution, as always, is completely and irrefutably irrelevant.
You showed that the Marine Corps ordered over 20,000 shotguns with 18.5" barrels. Where do you get 14" barrels?
"But the argument never was about 1934 NFA regulations."
The argument was about what the second amendment protects from infringement. And it doesn't protect shotguns with barrels less than 18" from infringement.