TX 200 Breech seal

[Vernal]

Looking at a TX breech seal, which has two "end rings" separated by a groove, I see the ring at one end seems to be slightly thicker than the one at the other end. Could someone kindly tell me whether there is a right way up to insert this seal into the cylinder?

[T 20]

The TX normally takes two identical O rings as the breech seal, Mike.





All the best Mick

[Turnup]

On mine the two O rings are both the same (BS 108 I think). They are cheap as chips so replace them both. A pack of 10 can be had on the-site-which-must-not-be-named for a couple of quid.

[Vernal]

The TX normally takes two identical O rings as the breech seal, Mike.
All the best Mick

Thanks Mick, I have got some identical O rings, but I also have a Chambers replacement seal, which is a nylon "double O ring in one" , and I thought I would try that as I am still not getting full power from the TX. The Chambers one seems to have different thickness ends.
All the best to you too,
Michael

[Phil Russell]

I have not seen the double version but it sounds interesting. Otherwise, as above, BS108. These also do the 'buffers' on the TX200SR.
Cheers, Phil

[Phil Russell]

Thanks Mick, I have got some identical O rings, but I also have a Chambers replacement seal, which is a nylon "double O ring in one" , and I thought I would try that as I am still not getting full power from the TX. The Chambers one seems to have different thickness ends.
All the best to you too,
Michael

I looked at the Cahambers site and could not find the 'double ring' seal you mention.
Can you tell me where on the site it is, please?
Cheers, Phil

[Vernal]

I looked at the Cahambers site and could not find the 'double ring' seal you mention.
Can you tell me where on the site it is, please?
Cheers, Phil

Now I am starting to worry! At least I start comforted by having two of the double seals, and the packet they came in bearing the inscription PW080 2X2 in front of me. I have taken a picture of them, but I can't seem to be able to post it (I could email it to you). I also have a clear recollection of seeing what is obviously one double washer on a parts diagram, and I have only bought TX spares from Chambers, but I do not seem to be able to find them on the current Chambers parts pic. I also checked the John Knibbs site just in case, but that too shows two separate washers. I would put it down to my advanced years if it were not for the physical evidence. As it is, it is a mystery.

[Phil Russell]

Now I am starting to worry! At least I start comforted by having two of the double seals, and the packet they came in bearing the inscription PW080 2X2 in front of me. I have taken a picture of them, but I can't seem to be able to post it (I could email it to you). I also have a clear recollection of seeing what is obviously one double washer on a parts diagram, and I have only bought TX spares from Chambers, but I do not seem to be able to find them on the current Chambers parts pic. I also checked the John Knibbs site just in case, but that too shows two separate washers. I would put it down to my advanced years if it were not for the physical evidence. As it is, it is a mystery.

Yes, mystery. I note the piston seal is PW030 on Chambers, the PW presumably meaning piston washer.

I will PM my email to you if that is OK as I am intrigued by the mystery .. not that I need a seal as I have some single O rings.
Cheers, Phil

[Vernal]

E mail on its way Phil. I have, for now, fitted the standard two O rings, but even with a massive (?) 52mm preload my short stroked TX is only just making 11 with JSB Express

[Phil Russell]

E mail on its way Phil. I have, for now, fitted the standard two O rings, but even with a massive (?) 52mm preload my short stroked TX is only just making 11 with JSB Express

Interesting. Now this may be a total red herring but I had a Mk1 TX (although I doubt the MK is relevant) that was running around 9. No matter what I did, new spring, new breech seals, new piston seal, increasing pre-load ... anything, I could not get it to increase.
Then I resealed the end plug on the compression tube. Perfect ... full power resumed, and adjustable. The O ring is 1.6mm x 22.1 but the thread needs more sealing support from the likes of a suitable Loctite. I have heard of the PTFE plumber's tape being used.

More on the double breech seal: further investigation, going back to 2018 suggests a chap called Bigtoe used to make them. That's all I know.

Cheers, Phil

[Turnup]

Interesting. Now this may be a total red herring but I had a Mk1 TX (although I doubt the MK is relevant) that was running around 9. No matter what I did, new spring, new breech seals, new piston seal, increasing pre-load ... anything, I could not get it to increase.
Then I resealed the end plug on the compression tube. Perfect ... full power resumed, and adjustable. The O ring is 1.6mm x 22.1 but the thread needs more sealing support from the likes of a suitable Loctite. I have heard of the PTFE plumber's tape being used.

More on the double breech seal: further investigation, going back to 2018 suggests a chap called Bigtoe used to make them. That's all I know.

Cheers, Phil

Similar experience with minen (a Mk 2). As well as the breech seal O rings the compression tube end plug O ring was also knacked. I removed it and used PTFE tape and it's still working and easily removed next time. Easy and cheap sop worth a try at least

[TonyL]

I've not experienced the issue myself, Michael, but everything I've seen relating to this issue on here has pointed to comp tube sealing.

[Vernal]

I must admit I haven't checked the end plug, so that is the next thing for me to try, thank you to all those who suggested it. I have just given the stock a coat of CCL conditioner, so I have plenty of time to play with the action while the oil hardens.

[Phil Russell]

Michael (Vernal) kindly sent me a photo of the 'double' breech seal and I am pretty certain the mystery is solved as it looks identical to the seal for an Hw77/97. I have held an HW seal up against 2 x BS108 seals and they are remarkably similar and I can believe they occupy the same space.
So... out of interest, has anyone fitted an HW seal in a TX or even used 2 x BS108 rings in an HW77? Maybe the HW would need a shim?

And, if you are going to remove the end plug... 27mm is the size. The end is not very deep so make sure the spanner / socket fits well. I needed to heat the end with a gas torch to soften the sealant ... not very hot but hotter than can be hand held. I heated for maybe 10 or 15 seconds playing the heat around the edge of the plug and it undid easily. When I did it, the fitted O ring came out unscathed by the heat.

Cheers, Phil

[Vernal]

Michael (Vernal) kindly sent me a photo of the 'double' breech seal and I am pretty certain the mystery is solved as it looks identical to the seal for an Hw77/97. I have held an HW seal up against 2 x BS108 seals and they are remarkably similar and I can believe they occupy the same space.
So... out of interest, has anyone fitted an HW seal in a TX or even used 2 x BS108 rings in an HW77? Maybe the HW would need a shim?

And, if you are going to remove the end plug... 27mm is the size. The end is not very deep so make sure the spanner / socket fits well. I needed to heat the end with a gas torch to soften the sealant ... not very hot but hotter than can be hand held. I heated for maybe 10 or 15 seconds playing the heat around the edge of the plug and it undid easily. When I did it, the fitted O ring came out unscathed by the heat.

Cheers, Phil

Thanks Phil, in answer

1, After over 80 years of persistent misuse, my memory sometimes takes a while to respond accurately, and on reflection it is just possible that I bought the seals at a not too distant gunshop, and maybe someone sold me those knowing they would fit a TX - apologies to Chambers if that is the case. You may well have solved that mystery.

2, I have just removed the end plug, which was very tight and I had used gentle heat (after removing my nice new breech seal) before seeing your post. There was no O ring at all, but the thread had been sealed with Loctite or something similar, (hence the need for heat) in very poor condition, so I could be hot on the trail of the missing power now. Many thanks.

Plenty of time to get a new O ring (why does t5he O ring box never have the size you need?) before the stock is useable again- or maybe PTFE tape will suffice.