It is for ease of maufacturing. There is no inherent weakness in this process. Fabrique Nationale (FN) pioneered this process, it is the way Browning P35 (High Power) barrels are made. Accuracy and barrel life are not adversly affected. They are quality barrels that will more than withstand several lifetimes of shooting. This is most often mentioned as a weakness by compeitors, since it is easy to imply a perceived although realistically non existant weakness. When is the last time you heard of a Browning barrel failure? Of course, there will always be those who claim their Springfield barrel failed, but most are those who impoperly altered their barrels, or more than likely is a repeated "gun shop" fabricated story. Then again, people do love to believe glossy advertising.