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.