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Thread: FWB Sport breech seal.

  1. #1
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    FWB Sport breech seal.

    Hi,

    Does anybody know the size of the breech seal for the Sport please?
    I have tried 2 metric sizes (11mm i/d x 2.5mm c/s and 11mm x 3mm) to no avail and I can't find a 2.75mm c/s so I'm coming to a dead end.
    It wouldn't be an imperial measurement would it?

    Thanks in anticipation.

    Gary.

  2. #2
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    from memory it's a 10 x 3, but I'll check in a few mins after brekkers.

    Vic T

  3. #3
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    The pack in the Garage says : Nitrile 70 Rubber O Rings, 3 x 10mm.

    However, I don't know if they are exact replacements, as although I've been using them for years, they might be the wrong material and hardness rating, but they certainly work on a temporary basis.

    HTH, Vic T

  4. #4
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    Quote Originally Posted by Vic Thompson View Post
    from memory it's a 10 x 3, but I'll check in a few mins after brekkers.

    Vic T
    As above for me.

  5. #5
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    Quote Originally Posted by Vic Thompson View Post
    The pack in the Garage says : Nitrile 70 Rubber O Rings, 3 x 10mm.

    However, I don't know if they are exact replacements, as although I've been using them for years, they might be the wrong material and hardness rating, but they certainly work on a temporary basis.

    HTH, Vic T
    Hi Vic,

    You sent me a couple last year when I bought some bits from you. They are a good fit but the first one has spread out a little over 6 months so I'm looking for replacements before the second one wears out. If I buy 20 they should last around 10 years which is fine by me.
    VTR 70 are widely available in that size so I shall get some ordered.
    When I measured the recess I read it as 11mm i/d x16mm o/d so that was the size I ordered but the fit was not tight enough so I ordered 11mm x 17 mm which were to tight, I never thought to go down to 10mm.
    By the way since you worked on my Sport it's been treated to a re-blue and the plastic trigger has been replaced with a Maccari one which cured the safety catch issue. It's looking georgious now as well as shooting spot on.

    Many thanks,
    Gary.

  6. #6
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    Chambers have them in stock

  7. #7
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    Quote Originally Posted by smallholder1 View Post
    Chambers have them in stock
    I too have seen them for sale from Chambers but at over £7 with postage I would rather buy 25 for a fiver now I've got the correct size from Vic.
    Thanks for the heads up though.

    Regards,
    Gary.

  8. #8
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    Agreed 10mm x 3mm
    Cheers, Phil

  9. #9
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    Only just got back to looking at forum, but this one caught my eye, as I had a little thought about 'Sport' breech seal sizes. Here's what I have in my 'Bible'.
    FWB issue = I/D 10.00 X 3.00 as normal; however this doesn't fit all guns; some breech grooves are O/D 15.70 X I/D 10.90 = 2.40 sec'n. with a groove depth of 2.30: a 'Std' 111 O ring will fit [10.78 I/D X 2.60 sec'n.] -- works OK. It's a tight fit and has projection above face. Also a metric 10.80 X 2.60 will work.
    ATVB
    abellringer

  10. #10
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    This is excellent information, thank you. Somehow I very much doubt if FWB had O rings made in a special size so the larger than normal ones must be a standard issue. A preliminary look tells me that a near equivalent is a German metric size 011-25 which has an 11mm id and cross section of 2.5mm ... so 16mm od. I have never seen one but wonder if it would fit? It is good news that a standard Bs111 will fit though. It is possible that a further search could reveal a closer match to your measurements.
    Isn't engineering wonderful?
    Cheers, Phil

  11. #11
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    I measured mine at 11mm x 2.5mm c/s and bought "O" rings of that size which were a loose fit. I am waiting for some 10mm x 3mm c/s and I'm thinking these will fit but the STD 111 looks like it may be worth a punt.
    Thanks.

  12. #12
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    Maybe I should have said: when I refurbed a 127 last year, I bought a new piston seal, spring and breech seal from Chambers. The breech seal supplied by Chambers was a 10 x 3.
    Cheers, Phil

  13. #13
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    Quote Originally Posted by abellringer View Post
    Only just got back to looking at forum, but this one caught my eye, as I had a little thought about 'Sport' breech seal sizes. Here's what I have in my 'Bible'.
    FWB issue = I/D 10.00 X 3.00 as normal; however this doesn't fit all guns; some breech grooves are O/D 15.70 X I/D 10.90 = 2.40 sec'n. with a groove depth of 2.30: a 'Std' 111 O ring will fit [10.78 I/D X 2.60 sec'n.] -- works OK. It's a tight fit and has projection above face. Also a metric 10.80 X 2.60 will work.
    ATVB
    abellringer
    I have just ordered some BS 111 "O" rings and will report back later.

  14. #14
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    Quote Originally Posted by gtfreight View Post
    I have just ordered some BS111 "O" rings and will report back later.
    The BS 111 "O" rings arrived today and I have fitted one. The gun was as quiet as it was with the 10mm x 3mm one and the fit was obviously not quite as tight so I thought all was good until I put it through the chrono and the mv was down by 50fps. So for my gun the perfect seal is the 10mm x 3mm c/s.
    I have just had a look at the auction site and a seller on there is advertising them in 2 sizes, 1 for guns with serial numbers below 5,000 and the other for higher serial numbers.
    If I'm correct in my assumations the earlier ones will be BS111 (10.77mm x 2.6mm c/s) and the later ones will be 10mm x 3mm c/s.
    If anyone has a pre 5,000 serial number Sport I have quite a few of these seals available.

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