This Ruger 300 Blackout magazine is made for Mini-14 rifles and is not intended for regular AR's. This magazine features steel construction and a reliable internal spring. 20 round capacity300 Blackout CaliberLaser-etched to mark caliberFits Ruger Mini-14Ruger pairs these reliable steel magazines with their rifles as they perform consistently and can be counted on for repeatable performance feeding ammo.If you own a Mini-14 chambered in 300 Blackout pick up a few of these 20 round magazines online today!Save time and money when you purchase 300 Blackout ammo at Ammunition Depot! Our online inventory of cheap ammo for sale is available from the top brands you know and trust.