“The United States military has a long history of adopting so-called wildcat calibers from the civilian world. Hell, the 5.56mm round that fills every M249 belt and M16 magazine has its origins as an experimental varmint round for civilian hunters — the .222 Remington Magnum.”

The rounds pictured above may soon be finding their way into the USSOCOM arsenal – read more about here:

http://www.wearethemighty.com/articles/special-operators-want-a-new-sniper-rifle-in-this-rare-caliber