Air Arms S400 regulator
Air Arms S500 Tuning Regulator By Huma-Air
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Huma-Air pressure regulator for tuning your Air Arms S400 airrifle.

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€ 85,00
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Huma-Air pressure regulator specially for the Air Arms S400 rifle.

Brings your rifle's performance to a higher level.
The regulator is vented to the atmosphere for excellent regulating behavior and no creeping up in power on the long term. We include a separate volume bus (plenum) matching the caliber and preferred power. The regbody is only 16 mm long and the regulator neck is round 13 mm with a length of 15 mm. So there is almost no lose of air volume in the pressure tube. A simple modification to your air rifle what will result in excellent shooting behavior and very consistent pelletspeed.


The benefits of the Huma-Air, Air Arms S400 tuning regulator are:

  • Higher accuracy of your rifle due to the elimination of the pelletspeed fluctuations
  • A constant pellet speed over the full working pressure range.
  • It will give you a better shotcount and a full flat shotstring immediately.
  • Adding a regulator to your airrifle will probably give you the biggest benefit in the tuning process.
  • Often the rifle will make less noise due to better balance in air usage 

When you order Huma-Air, Air Arms S400 tuning regulator you will receive:  

  • Your regulator preset to your own wishes
  • A pressure scale in Bar’s on the regulator, for fine-tuning or re-adjustment
  • We will include a “Huma -Air regulated” breech sticker
  • Fitting instructions as pdf download


Huma-Air Quality Control  

Huma Air regulators are CNC produced out of high grade aircraft aluminum and bronze. To guarantee a perfect product, every regulator is individually assembled, tested in a computerized simulation program and adjusted to the requested pressure. 
We only use high-end materials and our belleville springs are designed for critical applications to achieve the highest repeat accuracy. This gives our regulators a repeat cycle less than 1% difference.
Huma Air provides a 2-year warranty on their regulatiors. Excluded from warranty are shipping costs and parts that are subject to normal wear and tear such as o-rings and valve discs.




Pressure settings of the Huma-Air, Air Arms S400 tuning regulator


The Huma-Air, Air Arms S400 tuning regulator comes preset on the most common pressure setting, or we will adjust it according to your personal wishes. It is also equipped with a clear pressure scale label, so it's very easy to re-adjust or fine tune the pressure setting suitable to your wishes.

Our advice for choosing the best pressure range for your Huma-Air regulator:

  • Low pressure range:        60-110 bar for 16 Joule / 12 ft/lbs models.

  • High pressure range:       100-170 bar for all FAC rifles from .177, .22 and .25.


Shipping & payment

We ship worldwide with tracked priority shipping. We ship these pneumatic parts well packed for safe and undamaged arrival in the country of destination. As the purchasing party you are responsible for checking that this product is legal according to your local laws and regulations. We ship on your behalf and therefore Huma Air can not be held responsible for any legal issues in the country of the recipient.

You can pay safely and secure online by means of all major payment providers, like paypal, and credit cards companies.


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Benjamien - 31-12-2020 08:04

Zeer constante snelheid ben zeer tevreden , ook de link naar handleiding is zeer praktisch, mss alleen even zeggen dat het ,het beste is ventilatie gaatje aan onder de loop moet aangebracht worden niet aan de onderzijde

Philip Deighton - 23-08-2020 18:14

I am delighted with the speed of delivery. I had no idea there needed a breather hole in the air tube. I am saving up to get a new air tube as I am reluctant to use the original. I do like the visual aid to tuning. Thanks for the request for info. I will give feedback when finished with upgrade.

Jon - 20-05-2019 16:55

Well made product surprisingly easy to fit. Huma customer service is superb.

Steven Emm - 15-03-2019 12:57

Fitted to my AA S400 0.22 12ftlb.
As others have stated - well made, improved speed deviation between shots, easy to fit. Pressure set to 135bar, but able to compensate for the loss of regulated shots at the lower end (135 bar to 100 bar), by putting a bit more pressure in the cylinder (220 bar).
Currently used in this setup to minimise any other changes, but expect to tune it in the future to use a lower regulated pressure.

Keith Cater - 16-07-2018 20:58

This regulator is an extremely well made unit and with the built in adjustability, has allowed me to carry out other mods and still keep it under the limit. The online instructions and advice are second to none. Great work HUMA !!!! I can't recommend this unit or this company highly enough. I'll be buying from you again. That's a promise!

Bob Gardner - 06-06-2018 12:30

Reg fitted, 300 shots undertake to run the reg in as to say.
Then a string of 20 shots put through chronograph other than one shot max deviation between shots 3 FPS, the one deviation between highest and lowest was 6FPS which is top line, without reg deviations results was up to 12FPS
Very pleased with the results after having reg installed , will produce a further review in 6months time after significant use

keke - 09-10-2017 06:21

great product,in my air arms 500s extra fac i can now choose,depending on other modifications do i need 85shots/260m/s 200bar fill or 40shots/285m/s with same fill and same setting (120-125bar) on reg. i have Lane design anti bounce hammer on my gun and its second best modification on these guns.

Khamis Husain - 11-06-2017 12:15

Excellent regulator, simple installation and great consistency results with very low extreme spread and standard deviation.. my extra fac Air Arms S 410 shot count increased from 25 inconsistent shots to 50 very consistent shots. Worth the money. Thanks

Tim Higgins - 10-04-2017 03:06

I am very pleased with my huma regulator! It has transformed my AA S400 into an extremely versatile and adjustable rifle. As good as the air arms rifle are, I see no reason to own one without a regulator. And if you are purchasing a regulator, I see no reason to buy anything other than Huma. I believe I received outstanding quality for my hard earned dollars. I will be buying from Huma again.

Frakor - 29-11-2016 21:00

Works great, easy install and very consistant results.

Ken - 14-08-2016 17:49

Install was simple with web site instruction regulator went in good no leaks and shot count and accuracy are much improved throughout the fill cycle

Frank - 04-07-2016 18:20

Excellent regulator. I use it as an external in line regulator in a diy housing. Perhaps someday I'll fit it in my AA S510, but for now it works perfect.

Leslie - 25-06-2016 15:04

Straight forward to fit with very consistant results , A little tip don't cut the exsisting firing pot gentle heat it and it will separate leaving you with a finished item ready to fit .

Nev Baguley - 09-05-2016 09:13

Excellent regulator, quality engineering and simple to fit. My AA S400 carbine .177 is now capable of shooting a full HFT course with plenty of shots to spare. Very consistent.

Erik - 10-04-2016 21:36

I bought the huma regulators approximately 3 week ago,and i very happy the result .I installed my 3 Air Arms gun (S510,S510extra and TDR)
The installation was very easy and quickly
Thanks Huma This regulator are excellent

John - 06-04-2016 20:04

I bought the huma regulator approximatly 1 week ago and installed it immediately.
It sits in the cylinder perfectly and the installation is REALLY easy if you follow the fitting instructions on this website. You have to be patient and very carefull though when it comes to cutting the firing pot and drilling the breathe hole but as I said, don't panick, it really is easy.
Now I have velocities varying from 925 to 935 fps on 45 shots out of a 250 bars fill which is really great for the small cylinder of the air arms s510 (.22 FAC long version, not the carbine).

I TOTALLY recommand this regulator, time and money spent on it are completely worth it.

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