Barrett M82 Anti-material rifle,United States of America

The M82 is a short recoil semi-automatic firearm. When the gun is fired, the barrel initially recoils for a short distance (about 1 in or 25 mm), while being securely locked by the rotating bolt. After the short travel, a post on the bolt engaged in the curved cam track in the receiver turns the bolt to unlock it from the barrel. As soon as the bolt unlocks, the accelerator arm strikes it back, transferring part of the recoil energy of the barrel to the bolt to achieve reliable cycling. Then the barrel is stopped and the bolt continues back, to extract and eject a spent case.

Barrett M95 Anti-Material Rifle (AMR),united States of America

The Barrett M82 was the first notable American-made .50 caliber Anti-Material Rifle (ATR) when introduced in 1982. The line saw an evolution of sorts develop through the M82A2 which was made into a "bullpup" version (magazine feed aft of the pistol grip/trigger unit) which allowed for easier transport.

Desert Tactical Arms Stealth Recon Scout A-1 (SRS A-1),United States of America

The Stealth Recon Scout (SRS) is bolt-action sniper rifle developed by the American firearm manufacturer Desert Tactical Arms. (Now operating under the name Desert Tech) It was unveiled at the 2008 SHOT Show. It's known for it's bullpup design, which makes the rifle just as accurate as other rifles with similar barrel lengths, but staying as compact as an assault rifle or SMG.