The 6mm ARC started in AR-15s and promptly found a second home in short action bolt guns, and MDT's Gen2 polymer magazine keeps those rifles fed. 12rds stack into an AICS pattern body that drops into MDT chassis and any bottom metal built to the Accuracy International footprint.Gen2 is MDT's updated polymer design, and it gives up nothing in feeding reliability. Polymer also sheds the ounces that steel carries, which adds up on a rifle you pack between shooting positions all day.