Fast forward to 2007 when SIG Sauer, the U.S. arm of the now privately ... closer to that ideal would soon be on the way. The 556 Classic marked the first time a Swiss 550-style gun had become ...

Because of this manufacturers have entered into this market and developed rifles in this chambering, such as the SIG Sauer 556R. The 556R is built on the same rotary bolt, two-position adjustable ...