Advice on rifle fix please

[1873]

I've got an old Diana Series 70 model 79 that seemed a bit low on power - so I chronoed it. 3.5 ft/lbs!!! Yeah - just a bit low... So I took it apart and found the leather washer and buffer washer at the end of the piston disintegrated when I removed them. The spring didn't appear to be too bad but didn't need any compression to get it into the body - the length just fitted right.

Any advice on where to get spares or get an expert to cast an eye over it please? Does the spring sound ok or has it lost its tension? I know it's not worth much but it has sentimental value to me. Situated on the Suffolk / Essex border but could post it or travel a bit. Thanks.

[les allam]

Chambers gun spares may have the piston seals for your model 79.
Les..

[averageplinker]

If the spring is straight and the coils evenly spaced it is probably ok. As you have managed to get it apart you should be ok to fit a new seal and put it back together.

You will also need something like neats foot oil to soak/lube the new leather seal with.

Cheers Rich

[1873]

Thanks folks - much appreciated.

[Willenium]

I know there's a decent amount of preload on the spring in mine so maybe yours has compressed a bit now and isn't returning as much power as it could. Try it when you get your new seal and see what it's doing.

Just a quick query. How easily did you get it apart? I got as far as removing all the protruding parts but couldn't get the end block to slide out of the action. Was there a knack to it on yours or did it slide straight out?

[Rocket launcher]

Here
https://www.gunspares.co.uk/products/24470/G79/