Lubricating leather washers - some interesting observations

[andrewM]

Yesterday, I had one of my two Webley .22 Mk 3s chronographed. I was surprised to find it performing at only 7.5ft/lbs. This baffled because the last time it was tested, it was nearly 10 ft/lbs and, furthermore, I had then just fitted an unused, original Mk3 mainspring, bought from a helpful BBS collector here. I then realised that the rifle performs best with Superdomes and, furthermore, that I had not used it for some two years plus and that the washer had quite possibly dried out. To this degree, there was no indication, either, of any thin plume of smoke after firing.

I think, therefore, that I have solved the problem (and have added some drops of neatsfoot to soak for 24hrs) but it raised in my mind two questions:

1 Old air rifles with leather washers essentially require lubrication as part of their firing process, to achieve optimum performance. To this extent:

a) How does one achieve consistency in velocity? Too much oil leads to dieseling. Too little causes the washer to dry out. How is the balance achieved to smooth out high velocity, reducing to low velocity, before relubrication?

b) How does one gauge how much oil to use, therefore, and how frequently? I assume that a thin plume of smoke is ideal and, of course, regular use will require more regular lubrication. Non-use over, say, two years will probably also require lubrication.

Personally, I use neatsfoot compound, as supplied by the good people at Protek.

Regards to all,
A.

[AC99]

The Mk3 handbook suggests introducing a few spots of Webley oil through the open loading tap, close the tap allowing the oil to reach the piston and stand the rifle upright to allow the oil to soak in. Neatsfoot oil I think is regarded as a suitable equivalent in terms of preserving the washer although the original Webley oil had other properties.

As youngsters In the 50's our Mk3's got used a lot at weekends (300-500 pellets) and the summer holidays (even more) and I recall then that we oiled our guns on the Sunday night and were ready again for shooting the following weekend. The handbook also suggests firing one or two random shots before shooting begins to blow any surplus oil away also the book says the object of lubrication is to maintain velocity. If the gun isn't used for long periods it is best to lubricate the washer before storing.

Concerning dieseling, I think this only becomes an issue if very light oil with a high flash-point (eg 3 in1) is used which readily ignites on compression but if you stick to a few drops of Neatsfoot there shouldn't be a problem.

[andrewM]

Thank you for that interesting information. This historical knowledge and format in terms of essential servicing has become forgotten these days, in the age of synthetic washers, so it is most interesting to see what people were doing in the past.

It does seem, however, that this is something of an art rather than a science. Thus, one has to get right the quantity of lubrication and try to do it in such a way that the velocity remains as constant as possible. Quite a feat, methinks!

It is, of course, all part of the pleasure of owning these old air rifles.

Best
A

[Jerry Cornelius]

I wonder if the chance of out and out dieseling is overstated even with 3 in 1. I do lubricate leather washer guns with 3 in 1 or the equivalent and although it may be a bit smoky for a few shots I don’t think I have ever had actual dieseling, ie, detonation

I’m not saying it can’t happen but if you take it easy with the oil my experience is it’s not really a thing?

[Lakey]

My local gunshop used a 50/50 mix of 3in1 and Vaseline petroleum jelly, mixed in an old tin can and applied with a rather ancient crows feather ( I dont think the crow feather is essential ).

I guess the vaseline thickened up the mixture, and possibly cut down on the chance of detonation if any got ahead of the piston.

That mixture was used on all the spring piston guns.

Lakey

[andrewM]

Hi Lakey!

Good to hear from you after a while. Are you, per chance, going to Kempton next Sunday? I am thinking of attending and it would be pleasing to meet. On the other hand, visiting the event does put temptation in one's way!

Rgds
A