S200 (All Models)

Main Work 

Tench Regulator & Tune (Includes a full service)

The Tench Regulator & Tune packages are designed to make your rifle more consistent and air efficient, not more powerful. All sub 12 (non FAC) rifles are set to around 11.5ft/lbs after any work is done, keeping you well within the legal limit.

When the work is done by the RAT Works the action is extensively worked on to increase the performance, efficiency, accuracy and overall feel of the rifle. Almost every aspect of the rifle is modified, changed or enhanced in some way.

Air Arms

Fill Pressure when Tench Regulated







S4/5*0 Carbine




S4/5*0 Rifle








Below is a list of work under taken as part of the tune.

Hammer Mechanism

- Ensure the assembly is free of any oil, grease or debris which can cause consistency issues

- Re-finish hammer spring to a higher accuracy

- Polish the bearing surfaces in the hammer

- Custom made hammer weight & guide made if hammer is noisy

Loading assembly

- Loading probe modified for better airflow on some models

- Bearing surfaces polished and action block degreased

- If the 10 shot magazine system is fitted it’s often modified to work smoothly

- Lubricant is added to parts of the assembly to allow a smoother action

- Bolt lock up mechanism is polished for more responsive and smoother movement, also increasing the rifles consistency.

- Bolt flip upon firing is removed or reduced

Exhaust valve, transfer port & barrel

- The exhaust valve stem assembly is modified to run more efficiently

- The valve pressure is reset to give a better performance between heavy and lighter pellets

- The transfer port is modified to give a higher degree of air flow efficiency

- Crown of the barrel re-cut or polished if needed to increase the rifles accuracy

- The Adjuster in the transfer port is set with minimum restriction to allow a much more efficient use of air, 90% of the power setting is done with the hammer spring shortening. Only the final setting is done on this adjuster, which also helps with the FPS variance

Trigger assembly

- Sears are polished to a smoother finish

- Trigger adjustment screws are modified to give a more accurate contact point on the second sear

- Hammer and sear latching faces  faced & polished

- Trigger sear arm sides are polished and lubricated, and sometimes spacered to stop it rubbing on the action

- Trigger let-off is set to a comfortable and safe amount with a definitive 1st and second stage

- 1st stage travel can be reduced if desired

After the regulator is fitted and the tune carried out you can expect a shot to shot consistency of single figures as soon as the rifle has been worked on. A report sheet will be included with the rifle once work is complete detailing the shot to shot consistency through our SKAN chronograph, the rifle is held correctly in a mount to guarantee accurate results.  This consistency will improve further as the rifle is used.

S200 Hunter Package -Tench Regulator, shortened barrel and BSA air cylinder (250mm) with quick fill & gauge

This is an excellent way to shorten your S200 into the ultimate regulated compact hunter. The BSA air cylinder can be filled to 250bar to still give a high shot count from a very short rifle. The barrel is shortened at the same time to reduce the overall length and make a compact, high shot count hunting rifle. 

This package includes the following: - Tench regulator & tune

- Full service

- BSA air cylinder (250mm)

- New quick fill cylinder end with gauge

- Barrel shortened (same length as BSA air cylinder with quick fill)

Full Service 

The full service strips and rebuilds your rifle replacing all seals and renewing any worn parts to revamp performance while sorting any problems you may have such as leaks, low power, poor shot count or other faults.

Rifle Collection & Return Service

We can arrange a collection and return service from you via our fully insured next day courier if you are not local to us. This service allows air rifles to be collected and returned to your home address on a fully insured next day service.


1. We will only need the action/metalwork of the rifle, no stock, silencer, scope or shroud etc.

2. If applicable, please include the magazines or magazine you prefer to use with the rifle, if you have ever had any problems with them and we can investigate as required.

3. Please ensure the rifle is not cocked or loaded when packing for shipping! Rifles can still be charged with air.

4. Do not ship in a case/bag or with stock on(except for stock engraving or spring rifles) Shipping with these will incur a £25 storage/re-shipping charge.

5. Pack the rifle in a plain, strong cardboard box preferably with adequate newspaper or bubble wrap packing and mark the box with FRAGILE and DO NOT AIR UPLIFT.

6. Collection can take place any time between 09:00 and 18:00 on the day, we cannot specify a time unfortunately.


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