Home The 850 Mk2 Full Tune Refillable AirSource 9oz. Conversion HPA Conversion Kits & Accessories Contact & Orders

All Conversions include the full tune for the 850.

The 850 shown here with optional Half Shroud and scope.

      Tune with one refillable Air Source tank. This enables you to keep the clean look of the 850 Because 
      these fit right under the fore stock just like the standard AirSource tanks do.

                      Note: These are for CO2 Only and cannot be used for High Pressure Air.
                                  Doing so is not safe and will lead to serious injury.

Average .177 Muzzle Velocity at 85F on CO2:
(.22 is approximately 100fps slower)
                         Before: 750fps (7.9gr CPL)
                         After:   800fps
                         Same shot count as with standard Air Source tanks, around 160 per fill (at full power)

NOTE: You will need an CO2 Fill Adapter to refill the AirSource tank.
look at my Fill Adapter section under "Kits and Accessories"

Description Price Options Notes
Refillable AS Tank 35.00    If you take 2 of either of these, you get $5.00 off and no extra shipping
Take down / rebuild / Tune 100.00     Take down of the action and check and correct any of 
   the "common" issues that might be found.
   This will include:
   1. Shim for the barrel if  "sloppy".
   2. Full breech and port mod.
   3. Re crown Barrel to improve accuracy
   4. Check and replace o-rings (usually not needed on a new gun)
   5. Adjust / center probe on Breech
   6. de-burr and lube the action and hammer ways.
   7. Replace Hammer spring with Upgrade spring and new guide.
   8. Fit any other parts included in the tune. (discuss with me first)
   9. Put grub screws into empty sight screw holes if sights were
        removed. (on request only).
  10. Flow Mod Valve  
  11. Trigger mod.
Half Shroud by TKO with  Tune or

  115.00   $130.00 if bought separately
S&H 35.00 **    For USA (lower 48) Via FedEx only.
Total 170.00    

                               ** Shipping costs are estimated, this is an average price and will vary depending on what you packed it in
                                     when you sent it to me. (Heavier boxes like rifle cases will cost more to ship)