Air Arms S410 Pressure gauge seal and Fill port conversion?

[Humdinger]

Does anyone know how to find the U.S. equivalent of British O-ring size RN219-9? Or at least determine its dimensions? It seals behind the 1/8 BSP air pressure gauge on an old Air Arms S410. It won't seal with a replacement dowty seal because there is a recess below the gauge to hold an o-ring. The schematic for this model shows an o-ring and the original has dried out and is flat so I can't measure it.

Have any of you converted the old Christmas tree connector on the front into a Foster fill? Know of any U.S. vendor selling this conversion fill adapter kit? Pyramyd doesn't carry it.

Any feedback is appreciated.

 

[wildcj5]

Mac 1 did an S400 and an FWB P70 for me. You would have to contact him for exact details but he removed the gauge, ran a tap through the old threads and put in a foster.

 

[lineforeman]

RAW Rapidair makes one that yo just take the old one out and screw the foster in place. I did mine and it works great 

 

[Yo]

RAW Rapidair makes one that yo just take the old one out and screw the foster in place. I did mine and it works great

Yo right! Yo!

 

[BSJ]

It is a BS011 o-ring.

These dims. https://simplybearings.co.uk/shop/p80011/BS011-1.78mm-Section-7.65mm-Bore-NITRILE-70-Rubber-O-Rings/product_info.html

Good site for researching AA info. https://www.airarmsspares.com/air-arms-spares/