From the May 2005 issue of American Rifleman, John Treakle answers an NRA member's question regarding rifling types.

Most custom barrel makers cut the rifling into their barrels, as opposed to button rifling which more or less cold forges the rifling.

Machines and production cells perform deep drilling, reaming, and rifling for as many as 20,000 small-caliber firearm barrels per month – efficiently.