Lost Alpha Wiki

The Viper 5 9x18 is a unique weapon that appears in S.T.A.L.K.E.R.: Lost Alpha.

Light, compact and now redone to fit a more wide-spread caliber. This machine gun is a true find for beginning shooters.
- Inventory description


  • Unique variant of the Viper 5 sub machine gun. Main difference, besides the changed caliber, is the extended durability (-v1.4002) and the increased bullet speed (1.4005+).
  • One of the best weapons in the sub-machine gun class. During the last decades of the 20th century, it was adopted by the army and the police special forces units in many countries. When it was gradually replaced with more up-to-date models, it appeared on the black market and then the Zone.
  • Uses 9x18mm ammunition instead of the usual 9x19mm.


Lost Alpha

  • Weapon cannot be upgraded in Lost Alpha.

Developer's Cut

  • See Viper 5 for upgrades. Upgrade 5C is pre-installed.


  • Weapon cannot be repaired in Lost Alpha (-v1.3003).
  • It is not in effect, an already upgraded Viper 5 for a cheaper cost, since there is no possibility of repairing the unit.
  • Can sometimes be purchased from Sidorovich.
  • Available at Arnie (v1.4005).
  • Quest item for Nimble.
  • Weapon is not changed by the v1.4007 PRM Weapons Pack.


  • The inventory icon in Lost Alpha shows a HK53 instead of the actual Viper 5.