I won't be patenting the lower since that has been in use and existence for quite a while. You're right that the XCR market is too small to make it worth while to mass produce parts for it, but I like my rifle enough that I will make my own lower for AK magazines. If someone wanted to pay me enough for a few 80% lowers I could see doing that too, but its not something that I would do at a loss. I would rather just give the knowledge away at that point. No, the part I want to patent is small and unique but something that anyone could adapt to a rifle that utilizes AK style magazines whether 5.54x39 or 7.62x39.
Time is a great teacher...Unfortunately it kills all of its students.