Replacement o-ring for Tanfoglio Witness 1911 magazine??

[Mycroft]

Hi all

I put a new CO2 cartridge in my little-used TFW and all the gas vented out through the top of the magazine in a matter of seconds. So I removed the valve assembly from the magazine (the first time I have done so) and found the white tapered plastic part seals against a thin o-ring that has a metal ring that sits outside it.

The o-ring appears to be rather deformed - does anyone know the correct dimensions and where to source a replacement, please? It looks like it might be square section, less than 1mm thick and about 8mm diameter, but as it's deformed it's a bit difficult to tell.

Thanks

Mycroft

[Benelli B76]

Mycroft, the Witness magazine seal is made from PTFE/TEFLON which is not suitable for this type of application.It makes a good seal on a permanent joint, but because it is malleable and deforms is not suitable for a seal that is continually compressed and released, and will deform.The best material is polyurethane which is very resilient and hard wearing.I think Nick of magic9design can help you.

http://www.magic9designltd.com/

Baz

[Mycroft]

Thanks for the suggestion Baz, and I'm sorry I haven't responded sooner. I could have sworn I had set this up to email me when someone posted a response .

As it happens I also posted the same enquiry on the general airgun forum and a couple of people made the same suggestion, so I bought a new seal from Nick at magic9.

Initially the seal leaked - possibly because I had assembled valve with the metal ring around the outside of the new seal (as per the old seal). So I reassembled without the ring and it seemed to be better, although the gun was playing up (only actually firing a BB every other shot - although the action was recycling - and machine gunning). It may have been because the CO2 capsule wasn't pierced as cleanly as usual, but I haven't had a chance to try it again and investigate further. I must also ask Nick whether the new seal is supposed to have the metal ring on the outside.

Thanks again for the suggestion.

Cheers
Mycroft

[Benelli B76]

Got some flat sheets of 80 Shore A tdi polyurethane and now cutting out a few replacement seals for myself.

Baz

[Mycroft]

Out of interest what dimensions will your finished seals be?

I mentioned that I had some issues after replacing the seal with one from Magic9 - not implying there is anything wrong with the seal as I haven't had a chance to play about with it - so I wondered whether the valve might have screwed further into the magazine (I fitted the seal without the metal ring on the outside which may allow the valve to squish in further) resulting in less contact from the hammer when firing, resulting in less CO2 to fire the gun. Any thoughts?

Cheers
Mycroft

[Benelli B76]

8.0 mm O.D x 3.4 mm I.D x 1.6 mm thick.Push fit straight into piercing screw. I am talking about the CO2 cartridge seal.

Baz