Brit Seals - Piston & Breech Seals

[Brit Seals]

Brit Seals are precision CNC manufactured seals that offer super efficiency and performance whilst not requiring any resizing or run in time. Known to positively enhance the rifles shot cycle along with unrivalled longevity, it’s not surprising that some of the U.K’s top tuners are using Brit Seals.

Prices are as follows -

Weihrauch Seals
Weihrauch Breech Seal - £7.50
Weihrauch 25mm Piston Seal - £19.50
Weihrauch 26mm Piston Seal - £19.50
Weihrauch 30mm Piston Seal - £19.50

Air Arms Seals - please read advert for fitment to other manufacturers such as SMK & Gamo
Air Arms TX/Prosport Piston Seal - £14.50

Walther Seals
Walther LGU & LGV Piston Seal - £19.50
Walther Century Piston Seal - £19.50

Diana / Remington Seals
Diana / Remington 28mm Piston Seal - £16.50

Theoben Seals
Theoben MH 27mm Piston Seal - £25.50
Theoben AB 31mm Piston Seal - £29.50

FREE UK POSTAGE

INFORMATION

HW Breech Seal
Precision CNC manufactured breech seal that is designed to fit ALL Weihrauch break barrel and under lever rifle - HW25, 30, 35, 50, 70, 77, 80, 85, 90, 95, 97, 98 & 99. Not suitable for .25 cal

HW 25mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Weihrauch HW25, 30, 70 & older HW77/97 rifles with 25mm internals.

HW 26mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Weihrauch HW50, 57, 77, 85, 95, 97, 98 & 99.

HW 30mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Weihrauch HW35, 80 & 90.

Air Arms 25mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Air Arms TX200 & ProSport.

This piston seal will also fit - Diana, Gamo, Stoeger, BAM, SMK, Crossman, Benjamin & later BSA’s providing that they are 25mm cylinders and use the wedge type piston seal fitting.

Diana / Remington 28mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Diana Models 34, 36, 38, 46, 46E, 66, 75, Stutzen, 300R TO5 P31 & Remington Express

Theoben AB 31mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Theoben Models Sirocco, SLR88, Eliminator and some early Fenman rifles with this seal design and 31mm cylinder.

Theoben MH 27mm Piston Seal
Precision CNC manufactured piston seal that is designed to fit Theoben Models Fenman, SLR98, Olympus, Taunus and Sirocco 2000

Walther LGU/LGV
Precision CNC manufactured piston seal that is designed to fit Walther Models LGU & LGV

Walther Century
Precision CNC manufactured piston seal that is designed to fit the Walther Century

FITTING

Care MUST be taken to ensure that the cylinder is clean and free of burrs and sharp edges. A massive percentage of failed seals are caused during fitting. Lubrication we recommend a tiny amount of Standard Moly around the seal side wall and Advanced Moly (50% Moly) on the piston contact areas. Again use Standard Moly to lubricate the spring.

Maintenance greases can be found here -

Thread 'M & M Products - Maintenance Greases, Stock Refinishing Products and Aim Stickers UPDATED 1/2/26'

Feb 1, 2026

Hi all

Prices are as follows -

Maintenance/Service Products
Standard 5% Moly 25g - £4.50
Advanced 50% Moly 25g - £6.00
Silicone Grease 25g - £5.50

Target Shooting Products
Aim Stickers 24pk - £4.50

Stock Refinishing Products
Alkanet Oil 60ml - £8.00
Stock Oil 60ml - £6.50
Stock Wax 20g - £5.00

**PLEASE NOTE - ALKANET OIL CAN DIFFER IN COLOUR FROM THE PICTURE SHOWN, BUT WILL GIVE THE SAME RESULT**

+++WARNING - ENSURE THAT YOU DAILY DISPOSE CORRECTLY ANY CLOTHS & BRUSHES ETC USED WITH STOCK OIL, ALKANET OIL & STOCK WAX+++

####RETURNS - ONLY...

• Brit Seals
• Replies: 24
• Forum: New / Multiple / Member-Manufactured Items

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RETURNS - ONLY ACCEPTED ON UNOPENED AND UNFITTED PRODUCT

Thank you

 

[Alvaro]

Seals arrived today in timely fashion and in good order. Mike is a pleasure to deal with.

Having used Brits seals on another project, still going strong now a couple of years down the line, and being overwhelmingly impressed by the increased efficiency (I had to drop the preload quite a bit) with no need to resize, I can’t see myself using any other aftermarket seal.

Now to start work on the current rebuild!

 

[Brit Seals]

Seals arrived today in timely fashion and in good order. Mike is a pleasure to deal with.

Having used Brits seals on another project, still going strong now a couple of years down the line, and being overwhelmingly impressed by the increased efficiency (I had to drop the preload quite a bit) with no need to resize, I can’t see myself using any other aftermarket seal.

Now to start work on the current rebuild!

Thank you very much for your kind words mate