Steyr HS .50

The rifle is also available in the proprietary .460 Steyr round, developed for markets where ownership of the .50 BMG by private citizens is banned, but .46 rounds are not, such as California. The .460 caliber version is known as the HS .460.

The HS .50 M1 is an evolution of the HS .50. The biggest differences are: it is magazine fed from a five-round magazine feeding horizontally left from the receiver, has a longer top Picatinny rail and more Picatinny rails on the side, an adjustable cheekpiece, a newly designed fixable bipod, and a monopod at the buttstock.

Iran produces an unlicensed version under the name AM-50 Sayyad.[4] Because of its wide exports, AM-50 rifles have also been sold to or captured by many groups opposed to Iran, such as Syrian rebels.[3]

In June 2019, media organizations affiliated with the Syrian Government reported that Syria had begun producing an unlicensed variant of the rifle, dubbed the Golan S-01 in reference to the Golan Heights. It is reportedly manufactured by the Syrian Defence Industries Corporation, a state-run company managed by the Syrian Ministry of Defense. Unlike the original HS .50, the Golan S-01 fires the Soviet 12.7×108mm anti-materiel rifle cartridge. It is slightly heavier than the HS.50, weighing in at 13.5 kg and boasts an effective firing range of 1,600 meters, a 100 meter improvement over the previous generation of anti-materiel rifles used by the Syrian Army. It is also 100mm longer than the HS .50, measuring in at 1,470mm total length.[5]

AM-50 Sayyad used by Iranian Navy Takavaran

An Australian soldier trains an Iraqi soldier to use an AM-50 Sayyad.[7]

• Asa'ib Ahl al-Haq[8]
• Badr Organization[8]
• Hamas[3]
• Harakat Hezbollah al-Nujaba[8]
• Hezbollah[3]
•  Houthis[3]
•  Iran
•  Iraq - used by the Shia militia, Iraqi Special Operations Forces,[2] and the Iraqi Armed Forces.[3]
  •  Iraqi Kurdistan – Peshmerga[3]
• Islamic State[3]
• Islamic State Sinai Province[3]
• Kata'ib Sayyid al-Shuhada[8]
• Kurdistan Workers' Party (PKK)[3]
• Liwa al-Zulfiqar[8]
• Liwa Fatemiyoun[9]
• Saraya al-Aqida[8]
• Saraya al-Khorasani[8]
• Saraya al-Salam[8]
• Saraya Ashura[8]
•  Syria[3][1]
• Syrian Social Nationalist Party[3]
• Tahrir al-Sham[3]
• Syrian National Army[3]