TX 200 Breech seal

[Shed tuner]

the current (factory) TP is indeed an insert....

just glue in some brass tube, push it from the inside... thin tube will naturally flare a little and get lodged in the taper... If you are making from solid, by all means leave a little lip. if the end plug is off, very easy to tidy up afterwadds and add a minute champfer.

[Vernal]

the current (factory) TP is indeed an insert....

just glue in some brass tube, push it from the inside... thin tube will naturally flare a little and get lodged in the taper... If you are making from solid, by all means leave a little lip. if the end plug is off, very easy to tidy up afterwadds and add a minute champfer.

Thanks Jon, but I am not sure that I have any tube thin enough. What size finished tp should I be aiming for please?
My initial thought was to drill and tap the end plug to take an M8 threaded insert, then to make a new insert from apiece of 8mm mild steel rod, threaded with the die only closed enough to let the insert fit tightly into the end plug and the protruding stud reduced to 7mm dia as the existing one. Insert from the inside to get the projection right, then cut off the excess and file flush with the plug. Does this sound sensible, or am I un-necessarily complicating things?

[Phil Russell]

Out of interest I tried to find some thin walled steel tubing and failed to find any thinner than c 0.5mm and then the id was not perfect. I noted the use of radio aerial tubing and find that such telescopic aerials are available cheaply on the 'site' but do not have sizes of the tubes in the description. I am not about to sleeve a TX compression cylinder but if I was I would consider drilling the current TP out to take a brass or steel insert, maybe 4mm or so od with a new TP drilled through the insert at whatever is needed. My spare compression tube, which is a MK3, has a 3.6mm TP with smooth sides. I have the matching piston which has the latch rod extending 31mm beyond the skirt. The MK2 measures 45mm I believe.

But: if 3.6mm is the standard MK3 TP is there a benefit to sleeving it down even if everything else is standard? i.e. not short stroked or whatever.

Cheers, Phil

[Shed tuner]

But: if 3.6mm is the standard MK3 TP is there a benefit to sleeving it down even if everything else is standard? i.e. not short stroked or whatever.

Cheers, Phil

I thouth it was short stroked to MK2 specs

[Phil Russell]

I thouth it was short stroked to MK2 specs

I think there is confusion here (apologies) ... the piston and comp tube I am talking about is mine, a bog standard Mk3 ... 3.6mm TP and standard length piston from a MK3. Not a MK3 comp tube running a MK2 piston.

The system Vernal is talking about is a MK2 one mated to a Mk3 compression tube..... so I do understand that a reduction in TP diameter could be useful.

My question was 'is it worth reducing the TP on a bog standard MK3 to c. 3.2mm as used on a MK2'.
Cheers, Phil

[Shed tuner]

Thanks Jon, but I am not sure that I have any tube thin enough. What size finished tp should I be aiming for please?
My initial thought was to drill and tap the end plug to take an M8 threaded insert, then to make a new insert from apiece of 8mm mild steel rod, threaded with the die only closed enough to let the insert fit tightly into the end plug and the protruding stud reduced to 7mm dia as the existing one. Insert from the inside to get the projection right, then cut off the excess and file flush with the plug. Does this sound sensible, or am I un-necessarily complicating things?

I've done exactly that before, I think Nick has too, but it's too much work. Just get some brass or steel antenna tubing and find a bit that fits.

at mk1/2 stroke lengths, 3.2-3.5 is optimal, depending on lots of factors. If your piston is factory weight, smaller port (3.2) If lightened to around 190g, 3.5 is good. Ish.

[Vernal]

I've done exactly that before, I think Nick has too, but it's too much work. Just get some brass or steel antenna tubing and find a bit that fits.

at mk1/2 stroke lengths, 3.2-3.5 is optimal, depending on lots of factors. If your piston is factory weight, smaller port (3.2) If lightened to around 190g, 3.5 is good. Ish.

Thank you again Jon, I shall bear that in mind for the future, as this is a project gun which is as yet nowhere near its end state. However, the saga of the damaged TP is about to end in a very satisfactory, but completely unexpected way, and my comp tube will soon be fitted with a brand new and perfect end plug. Can't say too much, but I shall be spending some time in the future saying what a fantastic service a major manufacturer of British air rifles can provide.

I have acquired lots of interesting and useful information for the future from this thread, and I am most grateful to all who have contributed.

What a wonderful thing this forum is. Michael

[Phil Russell]

So pleased it all ended happily for you.
Cheers, Phil

[TonyL]

Thank you again Jon, I shall bear that in mind for the future, as this is a project gun which is as yet nowhere near its end state. However, the saga of the damaged TP is about to end in a very satisfactory, but completely unexpected way, and my comp tube will soon be fitted with a brand new and perfect end plug. Can't say too much, but I shall be spending some time in the future saying what a fantastic service a major manufacturer of British air rifles can provide.

I have acquired lots of interesting and useful information for the future from this thread, and I am most grateful to all who have contributed.

What a wonderful thing this forum is. Michael

Wow, what a brilliant and unexpected outcome.

Very well done, young sir (and that manufacturer).

Funnily enough I was watching a video on You Tube a few days ago. A South African one. Subject? "That" manufacturer.