Longsword Whisperhead SERSR

The Longsword Whisperhead is a weapon in Deus Ex: Human Revolution.

Background
The Longsword Whisperhead Suppressed Extreme Range Sniper Rifle (SERSR) is a weapon developed by Steiner Bisley.

Characteristics
This is a highly accurate long-range, bolt-action weapon that features a built-in sound suppression system that renders it virtually silent, making the shooter in cover almost undetectable at long range. The sniper can send large caliber rounds against distant targets. This is the ultimate one-shot-one-kill weapon.

Behind the scenes

 * The Longsword Whisperhead SERSR has been probably inspired by three rifles, the AIG Asymmetric Warrior for the adjustable stock and the Remington MSR - Modular Sniper Rifle and CheyTac Intervention for the bolt and the receiver.
 * According to the bonus 'Design Work' artbook, the Longsword Whisperhead SERSR uses the .416 centerfire round as seen on the 'Synergies Ltd.' sniper ammo box.
 * The Longsword Whisperhead SERSR has what appears to be a gas tube under the barrel like a semi-automatic rifle, although this rifle is manually operated. In third person view, the laser from the laser sight mod comes out of the front of this tube, despite that in the inventory it is shown as a module mounted underneath the weapon.

Locations

 * For anyone with the Tactical Enhancement Pack DLC installed, this weapon will be automatically added to the player's inventory at the start of the first post-augmentation mission.
 * I found this rifle in Seurat's Level 5 Security Storage Locker in Detroit Hub 1 after downloading the DLC then hacking the door for the first time. It is standing, muzzle up next to the box with 2 spare boxes of sniper ammo, which is good because it only comes with one bullet loaded even on Tell Me A Story difficulty.
 * One is located on the maintenance catwalk in Tai Yong Medical.
 * Another one is located in the Picus sub-basement.
 * Found on a red container on Belltower Dock, left to the main gate.
 * Found at Omega Ranch in storage room with a Lv. 4 hack panel.