The Heckler & Koch MP5 is a 9mm submachine gun introduced in the 1960s. Its roller-delayed blowback operating system produces low recoil and consistent accuracy, which contributed to its wide adoption by military, law enforcement, and special operations units worldwide. The MP5 is compact and light, well-suited to close-quarters work. Configuration options include retractable and fixed stocks, threaded barrels for suppressors, and accessory rails. Safety and charging handle controls are ambidextrous on most variants. The MP5 has served in counter-terrorism and close-protection roles and remains in production and active service. The civilian guns listed here are HK's own semi-automatic SP5 family (the full-size SP5, the short SP5K and SP5K-PDW, and the long-barreled SP5L) and the HK-licensed MP5 in .22 LR built by Walther. The .22 LR guns copy the MP5's shape and controls but run on straight blowback, not rollers.