Hatsan BT65, Hatsan Galatian II, Gladius

Hatsan BT65, Hatsan Galatian II
  • Hatsan BT65, Hatsan Galatian II
  • Hatsan BT65, Hatsan Galatian II
  • Hatsan BT65, Hatsan Galatian II
  • Hatsan BT65, Hatsan Galatian II

This Airgun Regulator is vented to atmosphere, but without drilling in the tank. Simple installation. Just unscrew the brass cap with valve and regulator only inserted into the tank and take out o-ring on brass body valve.

All HATSAN BT65, Hatsan Galatian II, Gladius airtube made in 2018 has smaller diameter.

Regulator which has to be ordered is Hatsan Flash which can fit in.

  • 250 char. max
Caliber: .177 /4.5mm
Required energy with regulator: 7,5J / 5,5 ft/lbs


High precion of regulation


Regulators for PCP guns. Unique technologic solution


A proud sponsor of the World and European Championships in HFT. We support shooters from all over the world


A 2 year warranty is provided for the goods. Best quality guarantee from Altaros.

Airgun regulator for Hatsan BT65, Hatsan Galatian II, Gladius

This Airgun Regulator is vented to atmosphere, but without drilling in the tank. Simple installation. Just unscrew the brass cap with valve and regulator only inserted into the tank and take out o-ring on brass body valve. This is all. Because some BT65 airtube has bad inner surface we added extra seal for avoiding airleak. Video installation is in the Video section.

Videos for installation and proper use regulator in the airgun Hatsan BT65

Hatsan BT65 video Installation

Unfortunately, Youtube deleted our channel, we will try to make new video soon.

In the meantime:

Video installation is very similar to P12 ( after the second minute ), most important part is to remove o-ring from valve. By removing o-ring you create venting hole for the regulator.

Setting output pressure on regulator

What to do when your output pressure increasing over time? This is most likely caused by dirt on o-ring on plastic screw.

In this video is shown how to remove dirt and replace o-ring. In video is used Gunpower regulator. Procedure is the same for other regulators.

Video how to take regulator out of regulator body

Correct clean air tube and regulator

Installation instructions for Hatsan BT65 air rifle pressure regulator

It is appropriate before reading the instructions look at the video instructions and then read the instructions for avoiding common mistakes during installation Hatsan BT65, Hatsan Galatian II, Gladiu

Unscrew airtube + cleaning

Before removing the brass plug we need to drain all air from airtube. When we unscrewing brass plug first time, airtube may need to be attached in a vice, but first, try to unscrew the airtube in hand with a spanner. To avoid scratches and rotation airtube in vice is advisable to wrap the sandpaper around airtube(rough side out) and attached it. After unscrewing the brass plug we clean o-ring and inside of the airtube. For cleaning, we use a foam or lint-free cloth. It is good to wash out the inside of the airtube with degreaser, or technical petrol, etc..

Mount regulator

Remove the O-ring from the brass plug. Spray regulators o-ring from the outer side with silicone spray. Insert the regulator into airtube so that it is possible to screw the brass plug and check the presence of the lower O-ring in the groove. By screwing plug we get regulator into correct position. Don't screw plug to the max, but leave a gap (between plug and airtube) about 0.5 mm.

Filling and draining air

Fill airtube with air through quick fill. ALWAYS drain pressure from airtube by using drain valve which comes with the rifle, never drain air quickly it can cause damage to piston in regulátor.

Setting pressure of airgun regulator

Altaros regulator output pressure can be set from 100bar (1450 PSI) to 150bar (2200 PSI) and after consultation of up to 170bar (2500PSI) which corresponds to the rotation of the screw behind value 150bar so that the line of the screw is pointing to the letter R. For a quick setting is on regulator engraved scale according to which the desired output pressure can be set. The total scale range of 100-150bar corresponds to approximately 2/3 turn Unscrewing, or screwing setting screw more than 1 turn may result in a malfunction of the regulation and scale will not show you regulated pressure. Groove on red marked half of setting plastic screw represents pointer which shows you currently set pressure on the scale. To change the pressure on regulator, just simply rotate the set screw with the flat screwdriver in the appropriate direction according to regulator scale.

Regulator pressure scale with three different settings

In this picture you will find an old scale (set at 100 bar), which we no longer sell.

Shipment contains

  • Altaros Regulator
  • 2 spare o-rings.


You must keep maximum cleanness in the entire pressure system (airtube and outer o-rings). Do not disassemble the regulator without previous approval, which will be awarded based on e-mail correspondence, where you provide the reason why it would be necessary to disassemble the regulator. In the case of a breach of this procedure you may damage the regulator function (fully assembled regulator is not simple and it is necessary to follow the correct procedure). For these reasons, the disassembly without previous consent, or failure exact installation procedure can not claim the warranty. Since regulator is not original part from the manufacturer’s, installation is on your own responsibility.

Results with installed regulator in air gun Hatsan BT65

18.1 grain 1.175g .22 graph is in FPS

Results for BT65-W in .25 (6,35mm) caliber with JSB Exact king

BT65 .25 regulator set on 140 bar without modification

BT65 .25 regulator set on 120 bar with modification

Compared with and without modification

Big thanks to Gregor from Slovenia for detailed results, he also made video where he is explaining all his modification on his BT65. You should definitely watch it:

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