Will parts suddenly start drying up?

You bet your ass, they will. Try to find a barrel for a 1300 these days. I ordered one from Brownell's, and at 9:24 the following morning, I got an e-mail stating that it was in stock and would be shipped. At 11:51, I got another e-mail stating that the item had been discontinued, and that my order had been cancelled. So I went to the Brownell's website and took a look in their factory parts section, and nearly all Winchester 1300 barrels had gone from "in stock" to "discontinued" within a matter of hours. Small parts, maybe. Barrels, forget it.