STEN Gun GBB Upgrade Guideline

The Full STEN Upgrade Kit includes a Nozzle with an end spring, a Hop-Up Chamber, a Magazine Gas Route and a Loading Lip. These components enhance gas efficiency, improve accuracy, and extend the maintenance life, making your STEN Gun GBB more suitable for skirmishes and more enjoyable.

Models that require the Full STEN Upgrade Kit are those released before February 2022, including:

  • STEN Gun GBB, MK.2, Early
  • STEN Gun GBB, MK.2, Late
  • STEN Gun GBB, MK.2(S), Skeleton Stock
  • STEN Gun GBB, MK.5
  • STEN Gun GBB, MK.2, Long Branch, T-Stock
  • STEN Gun GBB, MK.2, Chinese Contract, Lend-Lease Program, DNA Distributed
  • STEN Gun GBB, MK.6

The Partial Upgrade Kit includes a Nozzle, a Magazine Gas Route and a Loading Lip. These upgrades also improve gas efficiency and extend maintenance life. The models that require the Partial STEN Upgrade Kit are the BSA Variants, including:

  • STEN Gun GBB, Commando Grip, SOE Welsilencer
  • STEN Gun GBB, MK.2, BSA, Skeleton Stock
  • STEN Gun GBB, MK.2, BSA, T Stock

Instruction Videos:
Replacing Nozzle
Replacing Hop Up Chamber
Replacing Valve Knocker Assembly
Replacing Gas Route and Loading Lip

For the cumstomers in Japan, please contact your local dealer.

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