Check out the Quarter Circle 10, the pistol caliber carbine that refuses to be boring! While most of these bad boys are built around Glock mags, there are some wild alternatives out there, as you can see in our Photo Of The Day. And get a load of the QC-5 – it’s like an MP5 and an AR9 had a love child, complete with an AC-Unity MP5-style mag for all your 9mm needs. This thing is anything but ordinary!