FWB Sport breech seal.

[gtfreight]

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.

[Vic Thompson]

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

Vic T

[Vic Thompson]

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

[deejayuu]

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

Vic T

As above for me.

[gtfreight]

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.

[smallholder1]

Chambers have them in stock

[gtfreight]

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.

[Phil Russell]

Agreed 10mm x 3mm
Cheers, Phil

[abellringer]

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

[Phil Russell]

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

[gtfreight]

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.

[Phil Russell]

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

[gtfreight]

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.

[gtfreight]

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.