This 25 caliber regulated Umarex Gauntlet has many upgrades and has been power-tuned using the Hajimoto super tune kit (see hajimotoproductions. The super-tune includes a power adjuster, upgraded hammer spring, upgraded poppet valve, and O-ring kit. The trigger was also upgraded using Hajimoto's trigger re-work kit (the new 2-stage trigger kit was not available at the time). The stock 13ci 1900 psi Ninja air tank is most certainly too small for such a powerful gun. Therefore, the gun received a new 22ci Ninja air tank with a 1400 to 2400 psi adjustable regulator (see hajimotoproductions.The regulator is currently set at 2100psi and does not require the bottle to be depressurize before lowering the regulator pressure. Combined with the Hajimoto power tune kit, the average FPS/FPE increased from 883fps / 48fpe to 925fps / 53fpe using Benjamin Domed 27.8 grain pellets (see image). It pushes the lighter weight JSB Exact King 25.39 grain pellets at a blistering 949fps and 51fpe (see image).
There may be more power to gain with an increase in regulator pressure, but too much power may de-stabilize the pellets. I recommend testing slugs at the current settings before attempting to increase the regulator pressure.
If you plan to shoot indoors and want to decrease the power output, simply turn the power adjuster counterclockwise, using the included 5/64 Allen wrench. As a side note, the fill port is now on the bottom of the gun. Due to the configuration of the new pressure regulator, the shop that performed the upgrades had to cut an opening on the bottom cover for port access. The upgrades do not end there.
This gun also has a DonnyFL short shroud with a 1/2 x 20 moderator adapter. An aluminum air stripper replaces the factory plastic stripper (typically cracked from the factory). DonnyFL recommends using a 30 caliber Shogun moderator on the Gauntlet 30 cal to avoid pellet clipping. I have the Shogun and it does an awesome job reducing the bark from this rifle.
If you are not currently in the market for a moderator, just screw on the original shroud and factory cone for a quieter shooting experience. 2 - Standard stock 8 round magazines. 1 - Single shot tray. Pinty 4-16X40 Scope AO Red, Green, Blue Illuminated Mil Dot with Parallax.
1 - Dovetail to picatinny scope adapter. 1 - Picatinny bipod rail. 1 - Original Ninja 22ci air tank.1 - Original Shroud and cone. 1 - Set of adjustment tools. See Hajimoto's YouTube channel, and website (hajimotoproductions. Com), for a complete description of the upgrades to this rifle. The item "Umarex Gauntlet PCP.
25 Caliber Air Rifle 2252605 withHajimoto Power Tune Kit" is in sale since Sunday, January 31, 2021. This item is in the category "Sporting Goods\Outdoor Sports\Air Guns & Slingshots\Air Rifles". The seller is "markie725" and is located in Redford, Michigan. This item can be shipped to United States.