Webley Service Sear needs reprofile

[steve medlock]

I'm just bringing an old service back to life and have replaced spring and breach seal and done the usual cleaning and lubing.

Unfortunately the sear will no longer hold and its clearly not a question of a few passes with a stone.

Could anyone please tell me what profile I should be aiming for and is the sear mild steel/case hardened or is the whole sear a hardened part?

Thanks Steve.

[Troubledshooter]

I will email you a copy of the original sear blueprint.

[mark@mbb]

And me please if you don't mind

[Benelli B76]

If I made one would use gauge plate nearest thickness to the required item, then harden and quench in a light oil or cooking oil and afterwards temper to a straw colour. You could case harden ordinary steel but be careful not stone through the hard skin at a later stage.

Baz

[daveh]

Be careful when changing sears, if they do not both hold the piston in the same position, with the same pressure then when the top sear is activated and if the piston moves forward it may have enough stored energy to overcome the trigger sear!!!!!!![ the two sears need to be same physical condition, with the piston part of the sear also having been re profiled] I have a couple of holes in may garage door when a trigger sear did not hold when the barrel was closed. I think that this is the reason why some Mk 2s have had their top sear removed! Best of luck with your mod! Regards Daveh
[I think that this is the reason why the BSA with the double sear was not a success and dropped like a hot potato by BSA]

[deejayuu]

These may be of interest. Can do a tracing if need be.




Often think of "Stellite" facing for this sort of repair. Don't know if it's even still available.
Used to tip valve stems of Ford side valve engines when we were alive.

[steve medlock]

I will email you a copy of the original sear blueprint.

Thanks Troubledshooter. Unfortunately I still had an old email address in my profile which I've updated now. Could I ask you to send it again please?

Thanks
Steve.

[steve medlock]

These may be of interest. Can do a tracing if need be.




Often think of "Stellite" facing for this sort of repair. Don't know if it's even still available.
Used to tip valve stems of Ford side valve engines when we were alive.

Thanks for those. Its a strange shape really for a sear.
I've ordered some case hardening compound and will give that a try.

Steve.

[steve medlock]

Be careful when changing sears, if they do not both hold the piston in the same position, with the same pressure then when the top sear is activated and if the piston moves forward it may have enough stored energy to overcome the trigger sear!!!!!!![ the two sears need to be same physical condition, with the piston part of the sear also having been re profiled] I have a couple of holes in may garage door when a trigger sear did not hold when the barrel was closed. I think that this is the reason why some Mk 2s have had their top sear removed! Best of luck with your mod! Regards Daveh
[I think that this is the reason why the BSA with the double sear was not a success and dropped like a hot potato by BSA]

yes, thanks Dave - happened to me too.

[Troubledshooter]

Thanks Troubledshooter. Unfortunately I still had an old email address in my profile which I've updated now. Could I ask you to send it again please?

Thanks
Steve.

Blueprint re-sent.

[Benelli B76]

Thanks for those. Its a strange shape really for a sear.
I've ordered some case hardening compound and will give that a try.

Steve.

Looking at the pics the part seems to have been heated and quenched in oil to harden and not tempered afterwards. Do these sears normally snap off or do they wear at the contact point ?

Baz