Making new breech seal for Webley Service (and others)

[Phil Russell]

I have had need to fit a new breech seal to my Webley Service MKII. I did look at getting one from a 'spares' shop but was put off by price and the oft used term 'may need fitting'. Thus I may well have ended up resizing the bought option, so a seach for an alternative was called for. The old breech seal on my MkII is fitted on a removable brass carrier and was about 2mm thick. I thought that a new one could be made from pliable plastic and opted to firstly use a 2mm chopping/cutting board discarded from the kitchen but on reflection a lid off an old food container that was about 1.75mm thick may have been better.
The outer diameter of the seal is 0.5", the inner diameter that fits over the peg on the brass carrier is approx 7mm but I found 1/4" to be excellent for providing a good push fit on the carrier that stayed put. Cutting the seal thus required hole punches (wad punches) of 0.5 and 0.25". Using these to cut holes is no problem; the skill comes in getting the inner hole exactly lined up so that it is perfectly central to the outer diameter. Believe me when I say that this is very difficult to do freehand.
So a simple jig was made comprising a 0.5" diameter body about 6mm deep (to fit inside the 0.5" cutter) that had a central peg 0.25" diameter and 2mm high in the centre of one end. A few minutes on the mini-lathe with 15mm delrin rod and it was made. Now I accept that not everyone will have a lathe but it would be quite possible to make this jig using a pillar drill or other fixed power drill and files / emery paper. It could be made from wood or other material.
In use, a 0.25" hole is punched in the seal material and the jig fitted on top; the 0.5" cutter is then placed on top of the jig body and clouted. The result will be a perfect 0.25" hole in the centre of a 0.5" disc. Obviously different jigs could be made to suite different measurements for other seals for other rifles
The new 2mm seal was a good push fit on the brass carrier. When fitted to the rifle the barrel closed and provided a quite firm closure of the retaining rotary lever. I felt this was maybe a tad too tight so the seal and carrier was removed and the thickness slightly reduced using emery paper. It took very little effort to get a good closure and had me thinking that maybe if I had fitted the 1.75mm thick plastic the closure would have been good first time.
Will it last? I do not know but suspect it will. It has shown no inclination to move when fitted so I am hopeful. A chrono check showed perfectly acceptable performance.
Cheers, Phil

IMPORTANT: from the posts that follow it is clear that the thickness and maybe other dimensions of these seals can vary. Please adjust any fabrication to suit your seal.

[Troubledshooter]

A good idea, but the thickness of the original leather washer is 5/32" (4.0mm) and with the brass carrier it is 13/64" (5.20mm), so how did your 2mm seal provide a good fit ?
I prefer to get hold of some leather and make a washer from that. Offcuts from a cobbler or saddle maker are a good source.

[Phil Russell]

A good idea, but the thickness of the original leather washer is 5/32" (4.0mm) and with the brass carrier it is 13/64" (5.20mm), so how did your 2mm seal provide a good fit ?
I prefer to get hold of some leather and make a washer from that. Offcuts from a cobbler or saddle maker are a good source.

I bow to your superior knowledge of the Service but can only say that I do not know, but it does. The only thing I can think of is that my service has a barrel that comes further back in its fitting than is normal. I do not know how that can happen but will have a look to see ... the barell detaches easily and nicely when the push button is pushed, no play when engaged.
Seems to be a puzzle; but if the breech seal was any thicker it sure would stick out into the breech opening a long way.
I did get some leather from a 'bag maker' once but thought it very expensive just for a small offcut.
Cheers, Phil

[Troubledshooter]

I bow to your superior knowledge of the Service but can only say that I do not know, but it does. The only thing I can think of is that my service has a barrel that comes further back in its fitting than is normal. I do not know how that can happen but will have a look to see ... the barell detaches easily and nicely when the push button is pushed, no play when engaged.
Seems to be a puzzle; but if the breech seal was any thicker it sure would stick out into the breech opening a long way.
I did get some leather from a 'bag maker' once but thought it very expensive just for a small offcut.
Cheers, Phil

I took the measurements from a used Service breech washer belonging to a rifle I have in bits waiting to be reassembled, and I also have a leather replacement without the brass insert.

[deejayuu]

The way I read the OP it's 2mm of brass plus 2 mm plastic giving 4 mm then reduced a bit by abrasion.
Only commenting 'cos I'm interested and used 3/8th tap washer with no former in one of ours.

[johnbaz]

A good idea, but the thickness of the original leather washer is 5/32" (4.0mm) and with the brass carrier it is 13/64" (5.20mm), so how did your 2mm seal provide a good fit ?
I prefer to get hold of some leather and make a washer from that. Offcuts from a cobbler or saddle maker are a good source.

Could it be that when the original seal was removed, Only part of it was lifted, Sort of, Split and only 2mm actually removed?


I had to make one for mine, I can recall it being quite thick too!

I also had to make one for a Cadet Major, That was very deep at one edge but is wedge shaped, I had to glue two pieces of 4mm leather together, I then made a one piece punch on my lathe to ensure concentricity, It only worked once though as the edge folded over when it hit the hardwood that the leather was sat on!!

EDIT- Having now fully read the original post, It's obvious that it was all removed!


John

[johnbaz]

Couldn't find this pic of the one I made/replaced on my computer! (Typical!) but eventually found it whilst googling images!!

It looks as though there's swarfe all over it so I must have taken the pic straight after I fitted it and before I cleaned the waste off, No idea why there would be dust there though, And can't remember that far back!!



Doh!! It just came to me, I fitted the new bolt as it's own had been snapped, The peg that stops the bolt unscrewing, I had to grind down, I left it proud though for easy removal, The original was flush so I had a job getting it out (No room to drill!)..


John

[Phil Russell]

Thanks for all the comments... the plot thickens as they say. Out of curiosity I took the breech seal out of another Service this morning; this one a .22 as against the .177 of the original one above. The brass carrier seemed thinner and the seals I had made as above were a bit of a sloppy fit on it ... I am afraid I had destroyed the original seal in removing it (that's life). But it was thicker than 2mm, excluding carrier. In fact it was 3.75mm. I made a new one from leather c 4mm and 'sanded it down' to fit; giving some resistance to the bolt handle as it reached the end of its rotation. I punched the central hole at 5mm which, due to slight expansion of the hole as the punch went through the thickness of leather gave a good fit on the carrier spiggot. Total thickness of old seal plus carrier was 4.44mm, giving the carrier about .7mm thick.
I am now thinking that there is no standard fit / size for these seals; hence them being sold as 'may need sizing'. This .22 had not been fired for a very long time and gave a healthy (?) pleasant smell as the smoke cleared, no sharp crack though. Output was c 500 fps with JSB 16gn 5.5mm. I did not try with 5.6 pellets.
Don't you just love these old guns?
Cheers, Phil

[Troubledshooter]

I now have the original drawings, and the washers were originally red fibre, not leather.

[johnbaz]

I now have the original drawings, and the washers were originally red fibre, not leather.

Crumbs!!

Mine looks like red fibre, I'm wondering now if I got mixed up and made a breech seal for another gun rather than the Mk2!

If anyone else has a mk2 Service, Can they say if mine in the pic looks the same as theirs please?


Cheers, John

[Phil Russell]

Hi John .. the .22 washer I destroyed ... see post above ... looked just like your red one, mine was red and quite hard. The Webley pictures are fascinating as they even show that the washers when made had the slight depression factored in that takes the raised ridge around the barrel end. I had assumed that the action of the 'turn bolt' pulled the raised ridge into the washer material to form an effective seal.
Now ... where do I find 4mm thick red fibre washers or sheet .....
Thank you.
Mind you, my .177 is still sealing perfectly on a 2mm thick washer on top of the brass carrier.
Cheers, Phil