Webley Junior MK4 Barel Pivot Screw Thread Size

[AirGunDude]

Hey Guys. Whilst browsing a shop, I picked up a Webley Junior MK4 (1946-50) for £40.

The only problem with it is that the threads need cleaning. I need to know what size tap I need.

Thanks in advance guys

And also, when refitting piston, is any lubrication required? If so, what lubricant should I use (I believe it has a leather washer)

[torrens]

High agd, nice find; can't help with the thread size but the leather piston washer needs oiling. When I rebuilt my 50's Junior I stood the piston up in a tin lid of 3 in 1 oil to soak the seal overnight and wiped the excess off before fitting. Webley recommended neatsfoot oil ( available from saddlemakers!), some people will have other ideas but these little pistols are designed to be oiled regularly. Just mind the smoke cloud in the living room if you're about to have breakfast.....
atb torrens

[AirGunDude]

High agd, nice find; can't help with the thread size but the leather piston washer needs oiling. When I rebuilt my 50's Junior I stood the piston up in a tin lid of 3 in 1 oil to soak the seal overnight and wiped the excess off before fitting. Webley recommended neatsfoot oil ( available from saddlemakers!), some people will have other ideas but these little pistols are designed to be oiled regularly. Just mind the smoke cloud in the living room if you're about to have breakfast.....
atb torrens

Thanks for that

[AirGunDude]

Thanks for that

My dad reckons graphite grease would work... What's your view?

[torrens]

Hi, maybe on the spring but leather piston washers seem to work best with oil which gradually gets used then you top-up with a few drops after, say, a tin of pellets. The older Webley's had "oil" stamped into the cylinder to encourage you to do this. Grease probably slows the piston down a bit but it would work. If you Google "Pyramyd Air Blog" this is an American website with lots of info on airgun tests and maintenance, or just see what other people think here.
atb torrens

[AirGunDude]

Hi, maybe on the spring but leather piston washers seem to work best with oil which gradually gets used then you top-up with a few drops after, say, a tin of pellets. The older Webley's had "oil" stamped into the cylinder to encourage you to do this. Grease probably slows the piston down a bit but it would work. If you Google "Pyramyd Air Blog" this is an American website with lots of info on airgun tests and maintenance, or just see what other people think here.
atb torrens

I'll do a bit of research into the matter. The spring seems like new though, so I'll see about the washer...

Thanks