Watch the violent and amazing process Ruger’s barrels go through in the cold hammer forge.
What makes a rifle a rifle? Simple, its rifling. Not to be flippant, but quite literally the spiral grooves running the length of the bore are the defining features of the firearm. And dang important ones at that. Perhaps few things so drastically affected (positively) firearm performance than the 16th-Century innovation.
Nowadays, given modern manufacturing processes, there are many ways to outfit a barrel with rifling. The above video showcases perhaps the most dramatic method — the cold hammer forge. Produced by Ruger, the clips shows the company’s massive hammer forge in action and glory, not to mention some other steps in the process of producing a rifle barrel. In this method, the rifling is pounded into the bore through the use of the hammers and a carbide mandrill, which has a negative of the rifling pattern.
Interestingly, the barrel stock is actually over bored before hitting the forge in anticipation of its diameter shrinking with each blow of a hammer. What happens to the inside of the barrel, however, isn’t the only enthralling aspect of the process. Equally intriguing, the barrel comes close to its final dimensions — length and diameter — with its trip through the powerful and violent machine.