Question: who produced the modern bolt-action sniper rifle  which Steyr SSG 04 was the basis of 

Context articles: Yalguzag sniper rifle
Lobaev Sniper Rifle
Precision Sniper Rifle
T-12 sniper rifle
SV-98
Steyr SSG 04
GOL Sniper Magnum
Steyr SSG 08
Remington MSR
Steyr SSG 69

Yalguzag sniper rifle is a bolt-action sniper rifle that fires the 7.62×51mm NATO round used by the Azerbaijani Land Forces.
 Development of the weapon started in 2011 to 2012.
 Yalguzag means Lone Wolf in Azerbaijani
The Lobaev sniper rifle is a rifle line of custom-built bolt-action sniper rifles manufactured at the now defunct small, private company named "Tsar-Cannon Ltd" (ООО Царь-Пушка), which produced benchrest equipment and long-range, sniper and mountain hunting rifles in Tarusa, Russia.
 The Lobaev rifles are based on a single-shot bolt-action designed for benchrest shooting by Vladislav Lobaev.
 The chambering, barrel, stock, ammunition feeding method and other rifle characteristics are determined by the clients' preferences.
 With an accuracy of 0.3-0.2 MOA at ranges of more than 2 km, the Lobaev SVL is claimed as the most accurate sniper rifle in the world.
The Precision Sniper Rifle (PSR) was a program by United States Special Operations Command to replace all current bolt-action sniper rifles in use by U.S. special operations snipers with a single bolt-action rifle chambered for a large caliber Magnum chambering like .300 Win Mag, and .338 Lapua Magnum.
 The solicitation was placed on January 15, 2009.
 The contract was awarded to Remington Arms for their Modular Sniper Rifle.
The T-12 sniper rifle is a bolt-action sniper rifle produced for the Turkish Armed Forces by Makina ve Kimya Endüstrisi Kurumu in an effort to replace foreign produced sniper rifles with domestic Turkish products.
 (aka JNG-90)
The SV-98 ("Snaiperskaya Vintovka Model 1998") is a Russian bolt-action sniper rifle designed by Vladimir Stronskiy.
 In 2003 special operations troops were armed with the 7.62 mm 6S11 sniper system comprising the SV-98 sniper rifle (index 6V10) and 7N14 sniper enhanced penetration round.
 The rifle has been used in combat during operations in Chechnya.
The Steyr SSG 04 (German: Scharfschützengewehr 2004, English: Sniper Rifle 04) is a modern bolt action sniper rifle developed and produced by Steyr Mannlicher in Austria, as a complement to Steyr's SSG 69, using the same Safe Bolt System (SBS) action developed for Steyr's hunting rifles.
 It is also the basis for the Steyr SSG 08 and Steyr SSG Carbon.
The GOL-Sniper Magnum is a bolt-action sniper rifle designed by the German company Gol-Matic GmbH of Birkenau, Hessen.
 The rifle is available in tactical as well as sporting and match configurations.
 It is developed from Austrian Steyr SSG 69.
The Steyr SSG 08 (German: Scharfschützengewehr 2008, English: Sniper Rifle 08) is a modern bolt-action sniper rifle developed and produced by Steyr Mannlicher in Austria.
 The rifle is a further evolution of the SSG 04 sniper rifle, also developed and produced by Steyr.
The Modular Sniper Rifle, or MSR, is a bolt-action sniper rifle recently developed and produced by Remington Arms for the United States Army.
 It was introduced in 2009, and was designed to meet specific United States Army and USSOCOM Precision Sniper Rifle requirements.
 The MSR won the PSR competition, and is called the Remington Mk 21 Precision Sniper Rifle in U.S. military service.
The SSG 69 ("Scharfschützengewehr 69" = Sniper Rifle 69) is a bolt-action sniper rifle produced by Steyr Mannlicher that serves as the standard sniper rifle for the Austrian Army.