I don’t know, but maybe carolina feathers are different from the rest of the country…
Here’s my experience with how to split the feather, and toughness/stiffness:
– If the feather is dry, then I cut off the very tip of the feather and the thick end of the feather with a scissor. Then I can use my fingernails to split the tip. Then I can carefully pull the quill apart. No need for a razor.
– I have found natural turkey feathers to be tougher/stiffer than store bought feathers. To me, it only makes sense. Store bought feathers come from farm raised white turkeys that have been bread for generations to produce a lot of breast meat, not fly.
Setting aside all matters of economics and access to natural feathers, here is the question: If you want your arrows to fly straight, why would you use feathers from a bird that can’t fly at all?