Technical Advice Please - re Longbow Lubrication

[andrewM]

I bought a mint Longbow recently - the owner was a collector and put six shots down the barrel once a year and then returned it to its box. However, between buying it two months ago and after shooting probably less than 50 shots, the power has diminished by over 1/2 ft/lb.

The helpful gunsmith from whom I bought it, says that he thinks the cylinder needs greasing. The piston head and breech seal are as new, so he thinks this is the problem, which he will fix. I am just wondering if readers think I should suggest any other possibility.

Meanwhile, I looked at the Manual, kindly supplied to me by Troubledshooter, here. It says that occasionally, three or four drops of Weblube gun oil should be applied to the piston skirt, via the loading lever slots in the stock and body tube assembly. This is double-dutch to me. Does anyone know to what they are referring, here?

Also, the same drops of oil should be administered to the piston seal, via the air feed hole in the breech face. It then adds that serious damage could be done if there is over lubrication!

I was under the impression that unlike with leather washers, no oil should be introduced into the transfer port/air feed hole.

Any advice re the above would be much appreciated.

Many thanks.
A

[Troubledshooter]

Whatever lubrication you use, make sure it is synthetic oil like 'Weblube', and not mineral oil which Webley refer to as 'Weboil'.

[Geezer]

50 rounds is not really enough to form an informed judgement.

I'd say you need to do one of two things.

Either fire 500+ rounds through it in short order to see if it is currently going through a lube-related "phase" like a grumpy teenager - it may settle down to perform more consistently - or strip, clean, and re-lube/service/tune. What your smith is suggesting sounds to me like an unsatisfactory half-way house.

[andrewM]

Thank you, both, for your helpful advice, much appreciated.

I rather suspect that the rifle has not even been run in yet, given its condition and lack of use, so probably it needs some shooting. Still, it might have dried out over a period of some 12 years. Two further queries:

1 Do you know what the manual means when it says: "...three or four drops of Weblube gun oil should be applied to the piston skirt, via the loading lever slots in the stock and body tube assembly." What are the loading lever slots? I cannot see anything obvious, unless I need to remove the stock (not in itself simple because these are not ordinary screws for ordinary screwdrivers).

2 Is Weblube still available these days, given the closure of the factory? Presumably, this is not a silicone based lubricant - I have read enough about silicone on this site to have sleepless nights!

I will have to ask the gunsmith to carry out the lubrication procedure and perhaps the service and cleaning, as you suggest might be needed Geezer. I have not the confidence and tools to do this personally.

[hwtyger]

Forget lubing. It doesnt need it. Its not fitted with a leather pistonseal. Itll only cause dieseling or slowburn.
If it has new pistonseal than it certainly shouldve been relubed sufficiently.
Cilinder never needs lubing. Unless you totally degrease it with brake-cleaner of something like that, there will be suffficient lube in the manufacturing ribs.
Its probably just running in. Shoot another 500 pellets and see where it settles.
While waiting for that, give the barrel a good clean. Might be years ago, if ever

[andrewM]

Thank you for that, hwtyger.

I think the piston seal is almost certainly the one fitted at the factory but has hardly ever been used. The barrel looks spotless.

It is just rather strange that the power should fall so markedly. I will fire some more shots through it but it could have dried out, somewhat, especially if kept in a warm place.

A

[junglie]

it could be that the warm weather has affected it, see the recent thread on that subject.

[hwtyger]

Ive had magnums loose several Ftps of power after running in. So 0.5Ftp isnt very weird.
Temperature wont affect it that much; its not a Weihrauch topped up with grease before closing
Just enjoy it and see what happens.

[PCPShooter]

it could be that the warm weather has affected it, see the recent thread on that subject.

Most likely ....
My readings have changed from the bitter cold to tropical blast and now spring .....

[andrewM]

it could be that the warm weather has affected it, see the recent thread on that subject.

Could you kindly send me a link to the thread? I carried out a search but could not find it. I would be interested to see this. However, the warm weather had not had any impact on the velocity of my Webley Omega, because I tested this on the chrono too.

[TonyL]

As some have said, Andrew, this small "power drop" (if it is indeed a power drop) is nothing to worry about. If the rifle is shooting nicely and cocks smoothly without any undue noises, maybe leave alone?

Were you using the same pellets on those chrono runs?

Those "loading lever slots" relate to the cocking slot on the underside of the cylinder. You're quite correct to not administer any lube through the transfer port. However, if you wanted to, in my view there would be no harm in applying a little moly grease to the cocking slot, any visible spring coils, the rear of the piston and a little through the back of the slot, behind the piston and onto the cylinder wall.

[andrewM]

As some have said, Andrew, this small "power drop" (if it is indeed a power drop) is nothing to worry about. If the rifle is shooting nicely and cocks smoothly without any undue noises, maybe leave alone?

Were you using the same pellets on those chrono runs?

Those "loading lever slots" relate to the cocking slot on the underside of the cylinder. You're quite correct to not administer any lube through the transfer port. However, if you wanted to, in my view there would be no harm in applying a little moly grease to the cocking slot, any visible spring coils, the rear of the piston and a little through the back of the slot, behind the piston and onto the cylinder wall.

Many thanks for your advice, Tony, much appreciated. Yes, same make of pellets.

[BAD DAZ]

I would also put it down to the warm weather mate, I've had the same experience on many occasions, try the gun again in the morning before it gets too warm and you will probably find that the power has gone back to normal, this problem usually only happens when it is very hot, atb Daz

[andrewM]

I would also put it down to the warm weather mate, I've had the same experience on many occasions, try the gun again in the morning before it gets too warm and you will probably find that the power has gone back to normal, this problem usually only happens when it is very hot, atb Daz

Thanks for that, Daz. In my teens, I had an Airsporter. Once the temperature outside rose into the 80s, the power collapsed and the rifle shot low. It was hopeless - the accuracy was unreliable and it put me off BSA air rifles. I went out and bought an FWB, which did not have this problem and then sold that to buy an Original 45, which appeared not to have the problem either (I recently bought a second hand FWB - usual story - regretted selling it but still have the 45). I presumed, at the time, there had been some expansion of the Airsporter barrel and this created the problem but it might have been a problem within the cylinder.

Junglie posted a reply here, a few days ago, referring to such problems and a thread on this site dealing with this topic but I could not find it after a search.

I have not noticed the difficulty on other air rifles, however. It is something one would think the manufacturers had overcome.

[TonyL]

When those temperatures rise, the synthetic seals expand more than the steel cylinder, increasing friction, which is why springers generally make more power in cooler conditions.

Obviously dependant on seal to cylinder fit in the first place.

A member on here also experienced such a severe power drop in very cold conditions, however. Maybe the seal to cylinder fit was a little on the loose side to start with, but the seal had contracted to such a degree that it wouldn't generate power.