When most people think of roller-delayed blowback firearms of the Heckler & Koch pattern, the 7.62 NATO and 9 mm Luger cartridges are what come to mind. The 5.56 NATO cartridge also has a long history ...

** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. ** There are three calibers that are ...