Alexander Arms Ulfberht Magnum Magazine .338 Lapua 10 Rounds Polymer Black. 338 Lapua Magnum rifle. Maximum cartridge length is 3.75 inches. Specifications for Alexander Arms Ulfberht .338 Lapua 10 Rounds Magnum Magazine: Manufacturer: Alexander Arms Color: Black Fabric/Material: Polymer Magazine Capacity: 10 Round Caliber: .338 Lapua Magnum Condition: New Dimensions: 4 x 0.75 x 1.5 in 1.90 X 5.10 X 6.00 in Weight: 0.2 lb Width: 0.75 in Length: 4 in 6 in Height: 1.5 in Features of Alexander Arms Ulfberht .338 Lapua 10 Rounds Magnum Magazine The magazine is injection molded polymer and is manufactured specifically for the Alexander Arms Ulfberht .338 Lapua Magnum rifle. Maximum cartridge length is 3.75 inches. Package Contents: Alexander Arms Ulfberht .338 Lapua 10 Rounds Magnum Magazine Alexander Arms M-338MAG: Ulfberht Magnum Magazine .338 Lapua 10 Rounds Polymer Black