.300 WM caliber 3.850" mag length 3 or 5 round capacity on magnum rounds Weighs 8 ounces Heat treated and coated with Teflon for maximum durability This .300 win mag magazine can also be used for 7mm mag, .338 win mag, .280AI, 26 & 28 Nosler, .375 Ruger, 30-06 and 6.5x55 calibers. In some cases the feed lips may need to be bent inward or outward to set rounds at the correct height to feed. Maximum cartridge OAL that will fit is 3.750".