what is the big deal with barrels?
the barrel does not have a serial number,
so it can be bought by mail order,
just like any ordinary machine part.
He made his own for accuracy.
The Sheriffs department paid all his expenses to shoot in matches all across the country.
The big deal with barrels is there are very few manufacturers, which can be shut down by an oppressive government with little difficulty. No barrel, no gun. Insofar as they can be made at home, quality and production rate are nothing like writing large checks and having truckloads delivered from economically captive producers.