Hunter American Stock Ruger American Short Action (MAG931), with Ruger American rifles chambered in any caliber that are currently fed out of a STANAG magazine in the current OEM stock. Magpul created their new Bolt Action Magazine Well Hunter American Stock, STANAG for customers who originally purchased a factory Ruger American Ranch Rifle that fed out of a STANAG/AR magazine in the original stock and then went on to purchase Magpul's Hunter American Stock Ruger American Short Action (MAG931). Magpul's Bolt Action Magazine Well is a simple, drop-in add-on for the Magpul Hunter American for those who want to get their STANAG magazine compatibility back (magazines sold separately).