I actually should have made the complete statement... They can be done, but the cost of changing the machinery would drive the price to around $60 each, which is outrageous. Plus, the number of "bad" units produced for each good unit would increase
That really starts to cut into the return on investment.
The rest of that equation would be...
What barrel could be bored to support the system?
Who can do a 9" deep accurate bore at Freak diameter? (My current setup is maxed out at 6")
If you wish to invest around $1000, I can build a new machine and produce these. (Personally, I do not believe that you would ever be able to recoop the investment.)