Home Full Tune 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.

The 850 shown here with optional Full Shroud and Scope.

Tune and Conversion to High Pressure Air. 
Due to variations in the manufacture of all Airguns
velocities may vary by a maximum of 2% from quoted values

Minimum .177 Muzzle Velocity.
Before: 750fps (Stock 850 on CO2)
940fps 10.69gr Beeman Kodiak

Minimum .22 Muzzle Velocity.
Before: 645fps (Stock 850 on CO2)
940fps 15.89gr JSB Jumbo

Around 72 to 80 full power shots will take the tank from 3000psi (full) to 1800psi.

NOTE: Depending on how you intend filling this rifle, you will need a fill adapter look at my Fill Adapter section under "Kits and Accessories"

Description      Price Options Comment
 Full Tune and HPA Conversion





 Take down of the action and check and correct any of 
   the "common" issues that may 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 Upgraded spring.
   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 and adapter  
  11. Trigger mod.
  12. Convert to HPA

Note: Any parts removed from your gun to facilitate
         the tune or Conversion will be sent to you with
         the rifle.

Note: If your rifle was previously CO2
           Tuned  by The 850 store in 2011 or
           Later, this will only only cost $310.00
Half or Full Shroud by TKO with conversion
If bought separately, they cost $130.00
 S&H 40.00   For USA (lower 48) Via UPS only.
 Total 435.00    

                               ** 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 well above average to ship, you will be charged accordingly)