Heanel Mod VIII advice please

[fok]

I was recently given a very clean and original Heanel Mod VIII and I would like to use it but find it very twangy and harsh.

I've never owned a vintage airgun before so wondered if there's anything that can be done to make it shoot smoothly without it being a heinous crime in the eyes of the vintage airgun community?

I will never sell the gun so value / internal originality make no odds to me.

Do you collectables guys tune them to make them better? If so what's the score regarding what to do and who to do it please?

[Phil Russell]

If it was mine I would simply strip it, clean it all up, relube it and reassemble.
Sounds simple but be prepared for it to bite you ... might not, but it might. Can you chrono it before you start? A good idea if you can, not to test legality but to measure your success after the strip. Pitfalls: may well need a new piston washer, virtually certain to be leather. Might need new breech seal, again most likely leather. Neither are too difficult to make yourself ... several piston washer guides are on the web or I can send you a copy if you wish. New mainspring may be needed ... difficult to say without chrono data but if spring is broken (unlikely) or seriously bent or with obvious collapsed coils then you will have to (should) replace it.
Now, if you go for a new piston seal and washer and you carefully lube it all up after a good clean, do not be surprised if your fps has reduced a bit. I have seen this several times and I think it is a result of the old piston seal, even if falling to pieces, still making a good seal due to its inevitable accumulation of gunk. A new seal will get better...
Personally I do not fit new spring guides / top hats / piston sleeves to such old guns as I believe in shooting them as they were intended. It will be good fun as well.
Check to see if it is rifled or smoothbore ... the latter are not that common (I think).
Cheers, Phil

[fok]

Thanks for the comprehensive answer Phil. The gun has a rifled barrel and shoots around 7.7 fpe but is not very consistent.

I'm afraid work of that type is beyond me as my air gun stripping experience is limited to my Crosman fiddling.

Can you recommend anyone on here that would undertake such a job please?

[Phil Russell]

Hi fok, I can understand your reluctance to strip the rifle but these types of rifle are really quite simple things to get at. Have you found the Idiots Guide sticky in Collectibles? It does not include the Haenel but it does include similar ones like the BSA Breakdown pattern ... have a look at posts 55 and 112 there.
I have not stripped a VIII but would be very surprised if the sequence would not be: remove trigger guard ( will most likely have to remove the trigger adjuster screw first ). Find the bolt that secures the stock to the trigger housing ... most likely up through pistol grip or through stock under butt plate. Remove it. Now this can be stiff .. it may have a hex head or a slot. If you manage to remove it, put it aside. Turn attention to the trigger block can you unscrew it? Check that the trigger is not catching, if so just pull trigger as you unscrew. There should be no need to dismantle the trigger. If the block is very tight, do you have a vice so that you can clamp the cylinder in some rubber or similar pads while you apply more force?
If you succeed here then the block winds out, helped by the mainspring. I somehow doubt if the release tension is excessive but I always wear a leather glove when doing this operation, just in case. With the block off, the spring and guide comes out ... the guide will most likely be attached to the block. The piston cannot be removed until the link that pushes the piston back is released... at the breech or, if you wish, release the barrel pivot, remove barrel and link together. The link swings to about 90 degrees and simply unhooks from the piston. With that out of the way the piston will push out and you can inspect the piston seal. It will most likely be held on by a central screw.
Leather piston washers are not difficult to make. Indeed your main problem may well be finding the leather, about 3mm thick. Old belts, old bags from those holidays in Majorca or Greece are all good sources. Car boot sales are superb for this sort of thing. There are several guides to making the seals and it really is not difficult. In summary my method is to get a bit of leather maybe 15mm bigger than the piston diameter. It does not have to be a perfect circle, just crudely cut can be Ok but you need a hole in the middle to suit the piston screw. Get some leather softener as used for shoes and apply liberally. Fasten leather onto piston and then use a jubilee clip to start and form the cup by tightening slowly over a period of hours until the cup is formed and the clip fits firmly around the piston body . You can now trim the excess leather off the top of the cup, but leave the cup as a cup shape with about a 3mm recess .. sliding the clip up to act as a guide is a good idea. Soaking the new cup in an oil, maybe Neatsfoot is a good idea but I have used a silicon oil in the past or even good old fashioned engine oil although this is not terribly popular as it can lead to dieseling.
Eventually you will have a good cup to test for fit in the cylinder. It will most likely be too wide so tighten the clip a bit more for an hour or two. If still too tight, carefully use abrasive paper or even a file to reduce the diameter until it is a smooth sliding fit. At this point you should reassembly the rifle, even a test shot or two if you wish .... then leave overnight and then strip the piston out again to see if the seal sides have collapsed outwards such that the seal has a flat face. You do not want a recess on the seal surface. Simply trim the rim away if there is one. This all sounds very complicated but is quite easy when you come to do it, and very satisfying when you have done it.
If you do not fancy making the seal then I think some are available on 'the bay' or even from the spares people ... have the cylinder inner diameter handy but be prepared to have to fit the seal as above as even new ones are likely to be pretty hard leather that will need resizing.
Good luck
Cheers, Phil

[fok]

Once again, many thanks for taking the time to write such a detailed guide.

I'm not sure that such a lovely old thing should be my first foray into working on springers though