Air Rifle Mods/Parts

Hajimoto Productions Regulator Shim Kit For Umarex Gauntlet

I have put together a very easy and complete stainless steel shim kit so you can adjust your Gauntlets Regulator output. The shims that I have included give you a wide range of adjustability to mix and match different thicknesses to get the regulator to output exactly what you want. The shim kit comes with easy to follow instructions which guide you through the process as to what shims you need to add to typically achieve my recommendations for each Gauntlet Caliber.

The shim kit contains:

• 2 – #5 Shims.
• 1 – #3 Shim.
• 2 – #2 Shims.
  (Two #2’s = One #4 | Two #5’s = One #10 | One #5 + One #3 = One #8, and so on)

To take a stock G1 .177/.22 from the stock 1100-1050PSI to my recommended 1350-1400PSI you would add two (2) #5 shims (10).
To take a stock G1 .25 from the stock 1900-1950PSI to my recommended 2100-2200PSI you would add one (1) #3 shim (3).
The included two #2 shims are for minor adjustments if you have a finicky regulator.

DETAILED LESSON/EXAMPLE:
Let’s say your .22 Gauntlets regulator only puts out 1300PSI after installing the two #5’s when it should be 1350 to 1400PSI, you would add one #2 for a total of 12 to help get it there. If after the addition of the one #2, you’re still 50psi short so you would pull out the #2 and use the #3 for a total of 13.

Always use a regulator output tester to confirm the output pressure of your regulator. It is the only safe and sure way to properly adjust the pressure of your regulator.

You have to fill and purge so the Belleville washers settle into the new preload. Be sure to slow fill your bottle the first time only to 500PSI and then purge it, fill slowly a second time to 1000, and then purge fill the final time slowly and watch to be sure the reg has settled and does not exceed your target pressure. If it does exceed your target pressure, stop filling, purge and shim less.

If you rapid fill, there is a good chance you will pop your burst disc.