MDT metal AICS magazines are manufactured from high strength steel and finished with Cerakote for ultimate durability and corrosion resistance. The 300 Win Mag magazine can also be used for 7mm Rem Mag, 30.06, 6.5x55 and similar cartridges by adjusting the feed lips. 3.560" 300WM for MDT chassis systems for Tikka long action rifles (270 Win, 30-06, 300 WM etc) Notes: All MDT chassis are manufactured with a 3.715 magazine well. The Remington Tactical Chassis Rifle and 338 Lapua XCR rifles use a 3.775" magazine not available from MDT Tikka T3 long action calibers in MDT chassis you must use the 3.560" option. Will not work with 300 Remington Mfg: Mdt