Compatible with .300 Winchester Magnum; 5-round Capacity; Manufactured from high strength steel; Finished with Cerakote Elite for the ultimate in durability and corrosion resistance; Standard length long action magazine in an MDT Chassis is 3.715" unless otherwise noted in the description stating CIP or 3.85 for the longer magazine well; Remington Tactical Chassis Rifle and 338 Lapua XCR rifles use a 3.775" magazine not available from MDT; Tikka T3/T3x and Savage Axis long action calibers in our chassis you must use the 3.560" option; Will not work with 300 Remington Ultra Mag, 300 Weatherby, and similar cartridges