The PMAG 10 5.56 AC is a polymer 5.56×45 NATO (.223 Remington) magazine designed for short action Accuracy International Chassis Systems (AICS) pattern bottom metal, including the Bolt Action Magazine Well for the Magpul Hunter family of stocks.Designed with many of the same qualities that make our PMAGS the most reliable and durable in the world, the PMAG 10 5.56 AC features GEN M3 technology, including a self-lubricating follower, a stainless-steel spring, and constant-curve internal geometry for smooth feeding. It also incorporates offset feed lip geometry that maximizes bolt face engagement, guaranteeing reliable feeding and solving the bolt face issue common to other AICS-pattern magazines for 5.56 based cartridges.Like our other Magpul bolt action magazines, it features a paint-pen dot matrix for visual identification and a flared base plate for positive control and ease of retrieval. Designed from the ground up to solve the challenges of feeding 5.56/.223, the PMAG 10 5.56 AC sets the standard for bolt action magazine technology.Made in the USA.TECHNICAL SPECIFICATIONSMore InformationCaliber 5.56 x 45Platform Bolt ActionCapacity 10Weight 2.71 oz.Height, max 5.01 in.Length, max 3.05 in.Other SpecsWidth: 0.97 in. Top, 0.88 in. BaseCompatible with short action AICS-pattern bottom metal and 5.56×45 NATO/.223 Remington cartridgesAccepts cartridge overall length (COAL) of up to 2.39 in.Use with other calibers such as .300 AAC Blackout is not recommendedDue to the feed geometry dictated by the .223 Remington cartridge and the Ruger American overall receiver length, this magazine is not recommended for use in the Ruger American rifle. While it will be possible to insert the magazine into Ruger American rifles that accept AICS-pattern magazines, function and reliability may be heavily compromised.