Advice please re lubrication of leather washer/Mk3

[andrewM]

I think I have finally cracked this conundrum but would appreciate readers' views.

I was aware that leather washers required occasional oil, via the transfer port. With my Original 45, the amount is a couple of drops every 1500 shots - very little. However, my Webley Mk3 seems to be thirstier. I have found that the power drops, perhaps by 20%, without regular lubrication. I know this because I have inspected pellets, fired against a flat steel target holder (I do not have a chronograph).

It was therefore a question of knowing when to lubricate. I have now reached the view that this needs to be done every 200 pellets, approx. At that point, I fill the loading tap to 50% (I use Weboil or neatsfoot compound), work the cocking lever and then allow it to soak in overnight in the upright position. I then shoot half a dozen pellets to clear away the excess and then the power returns to what I believe is probably a tad over 10ft/lbs (I can gauge this from the flattened pellets).

With the Original 45, there would be a loud crack with anything more than a drop or two, with serious dieseling as the oil exploded under pressure. That is not the case with my Mk3; the noise is more or less unaltered.

I am aware these rifles were made to function with oil; perhaps a degree of minor dieseling is a factor in the power.

Quite possibly, the size of the leather washer is also a factor. Perhaps, when it dries, the washer shrinks, thereby reducing the power.

(My Mk3 is a 1973 model; the tap works well and there is no leakage. On a good day, I can just about manage 3/4in groups at 25yds).

I should very much appreciate comments on the above. Is my situation typical? Am I over-oiling? Could it be the mainspring needs replacing if I am relying too much on oil for performance? It seems to me, however, that I have just about reached a sweet spot and that once the rifle ceases to smoke, new oil is required - ie every 200 shorts, approx. Does this sound about right or are there other things at work, here?

It seems the older springers have quite a number of factors to consider, to reach optimum performance. This, I find, rather adds to the satisfaction of firing them.

[slow_runner]

I think I have finally cracked this conundrum but would appreciate readers' views.
With the Original 45, there would be a loud crack with anything more than a drop or two, with serious dieseling as the oil exploded under pressure. That is not the case with my Mk3; the noise is more or less unaltered.

Hello Andrew
Strange; could your Original 45 have a synthetic seal?

[45flint]

I really think you need a Chrony to really know where you are? Why guess, this is the best tool you have as a airgunner? I thought Webley oil back in the day was mineral oil? I’ve been using 30 weight non detergent. Clears quickly with a few shots. I’m getting 10fpe but have not shot it enough to really need a relube. The guys here should know MKIII will be interested in their comments

[andrewM]

Hello Andrew
Strange; could your Original 45 have a synthetic seal?

No, it is a leather seal and I still have the instruction leaflet which advises on the oiling. I think, however, that these rifles diesel rather more easily because of the power factor, which does not appertain with the Mk3. Probably, on the occasion concerned, I put too much oil into the chamber, given it was over 10 years since I had last used the rifle.

[andrewM]

I really think you need a Chrony to really know where you are? Why guess, this is the best tool you have as a airgunner? I thought Webley oil back in the day was mineral oil? I’ve been using 30 weight non detergent. Clears quickly with a few shots. I’m getting 10fpe but have not shot it enough to really need a relube. The guys here should know MKIII will be interested in their comments

Yes, I will have to get a chrony but the pellets are flattened after lubrication and then the velocity reduces after the oil dries out. At that point, the pellets are only half flattened, with less of a diameter. Thus, there is a significant reduction in power but whether it is 20% or 30% is hard to tell. I had the gunsmith test it after it was oiled and the velocity was about 10.2 from recollection - so about the same as yours, which sounds about right for this rifle.

When I first bought one of these (when I was 13), the rifle smoked after firing and was designed to do this. I cannot recall what oil we used in those days but probably '3 in 1'. I think it cost a tad under £30 then - £28 seems to come to mind. I bought another just under two years ago. They seem to have a character to themselves.

[Geezer]

Quite possibly, the size of the leather washer is also a factor. Perhaps, when it dries, the washer shrinks, thereby reducing the power.

I think you’ve hit a nail on the head. It can’t be the only factor (swept volume, TP size, etc), but it appears true that different leather seals perform differently and need different levels of maintenance.

My guess (guess) would be that your Diana seal is in better condition and works better at the dry end of the spectrum, and your Webley one is less well off, and therefore “thirsty” and seals poorly when not well-lubricated.

[andrewM]

I think you’ve hit a nail on the head. It can’t be the only factor (swept volume, TP size, etc), but it appears true that different leather seals perform differently and need different levels of maintenance.

My guess (guess) would be that your Diana seal is in better condition and works better at the dry end of the spectrum, and your Webley one is less well off, and therefore “thirsty” and seals poorly when not well-lubricated.

Very helpful, Geezer, thanks. I would never have known this, before I joined the site but I think I have been on a most helpful learning curve, here. This, in turn, also suggests the leather seal might require replacing or, at least, inspecting. Alas, I am less confident about opening up the internals! On the other hand, thinking further on the point, a better fitting seal might expand too much if lubricated, with a restrictive effect. Hmmm, a fine balance is required. In addition, one just cannot tell what has happened in the 45 years since the rifle left the factory.

[45flint]

Any comments on neatsfoot vs ND mineral oil?

[nige346]

I've only ever used neats foot as a pre soak oil for the seals never as an ongoing lubricant, with regards to the MK3 I have restored quite a few of these, Be careful if the rifle is dieseling, I have come across a few where the cylinder has expanded due to this, seems more common in MK3's than other rifles I have worked on, If the rifle is only producing decent power with oil added and therefore dieseling it would suggest the seal needs replacing, These aren't high power rifles and a chronograph may show it is already producing expected power, The 45 is more powerful by design so not really comparable. In my experience actual seal lubrication would normally be a couple of drops over 1000's of pellets if the seal is in good condition, If replacing size the seal, pre-soak in neats foot to soften then soak up any excess oil, put the rifle back together and let the seal sit un-cocked against the spring pressure, This will allow the seal to size correctly in the cylinder, avoid the temptation to cock and fire for 24hrs, The end result will be a seal that seats properly and seals perfectly against the cylinder wall's.

This is how I was taught and it's always produced good results for me, I'm sure others will have their own methods which are probably equally correct,