Heckler & Koch Rifle Magazine MR556 5.56mm 30 Round Black 10. 56 mm magazine. Originally developed by HK for the British L85 (SA80) & L86 weapons this curved 30-round magazine has been combat-proven by U.S. special operations forces and foreign military units. The 30-Round Steel Magazine features a well-executed design select materials anti-friction maritime surface finish advanced spring material attention to production tolerance and steel magazine housing and follower. Specifications for Heckler & Koch MR556 5.56mm 30 Round Rifle Magazine: Manufacturer: Heckler & Koch Color: Black Fabric/Material: Stainless Steel Magazine Capacity: 30 Round Caliber: 5.56x45mm NATO Gun Make: Heckler & Koch Gun Model: Heckler & Koch MR556 Gun Type: Rifle Quantity: 1 Package Contents: Heckler & Koch MR556 5.56mm 30 Round Rifle Magazine What firearm models does the manufacturer say Heckler & Koch MR556 5.56mm 30 Round Rifle Magazine is compatible with? The manufacturer suggests that Heckler & Koch MR556 5.56mm 30 Round Rifle Magazine is compatible with Heckler & Koch MR556Heckler & Koch 251770S: Rifle Magazine MR556 5.56mm 30 Round Black 10