The truth is, why would anyone want to develop a product offering for a customer base comprised mainly of whining titty-babies?
What I mean is you would be selling a semi-finished product to a group of people who would scrutinize it with a microscope and find fault in every detail, and they'd neglect buying it until you gave up and sold off your inventory cheap. Then they'd break up into two groups: the ones who bought 8 sets of .410 barrels for next to nothing (we'll call them the Chest Thumpers) and the ones who moan for years that they sure wish you (the villainous maker) still made them because when you were making them they were still helping pay off their Aunt Louise's hysterectomy and they couldn't afford a set. This group, the Victims, will pester you with phone calls and emails offering you the opportunity to make amends if you will tool up to make them one set of 14 gauge 36" tubes - if the price is right.
