The Lesser Spotted Original/Diana 35

[T 20]

Hiya Mick.
I have huge sympathies with your predicament and you've hit the nail on the head as to why so few D35s get anything other than a basic service to keep them going. It's an absolute balls ache stripping the gun down. I've not been inside a 35 but having done so to a 50 that trigger takes a bit of fiddling to get right so finding all your efforts have resulted ina gun that wont clock is the ultimate sinking feeling. As you know the later modular triggers are a lot easier to work with.

Being butally honest though your pain and suffering will help others through this article by taking away some unknowns and giving some good information on achieving given results so you are doing a good deed.

I think you are right about the ditching the leather seal. To me with airguns I ether buy a gun to keep it 110% original so it's a factory example of what was produced (I've always GOT that concept), but at other times if I have an example of a gun a little less than pristine then this is fair game for some serious tinkering and improvements. It seems to me your gun falls into this category. Leather is a durable material and has stood the test. But to move forward and get the best potential from a gun you need to move to modern materials and gain the benefit of better consistent results. After all we have ditched mineral oil in our cars this long time for oils with friction reducers built in that reduce wear and add longevity lower emissions etc. To improve a gun leather needs to be parked up. I've had many debates with a fellow member here about his leather fetish and refusal to accept modern materials in older guns

So thank you for your pain and suffering in the name of giving the rest of us some knowledge to undertake similar mods to our own guns. Though each gun is an individual unit, your results would give a strong indication as to general outcomes. For me the M&G guide has to be ditched in any improvement to remove twang. Is there merit in gliding the piston whilst at it? In for a penny philosophy comes to mind......

Hope you keep going and well done with the results thus far.

Dave

Cheers Dave.

The inability for the gun to cock was really a rookie mistake by me in not taking note of how the 3 ball D35 trigger mechanism set itself.
On the T01 trigger the piston latchrod is solely responsible for setting everything, which is why the whole trigger and back block is removable as one unit.
On the D35 the latchrod enters the centre of the trigger unit and passes the point at which the balls can drop onto the reduced section of shaft.
Cocking further allows the tail of the piston to push the sleeve shaped sear which locks the balls in and eventually the trigger sear drops in the hole in the sleeve and the trigger is set.
I only cut enough off the guide for the balls to drop onto the shaft and I didn't take the movement of the sleeve into account, once I'd cut another 10mm off the guide everything worked as it should.

Yes this D35 doesn't owe me much and was only bought for sentimental reasons but as is my habit, I feel I must tinker with it to see what it will do.
Though it's an absolute ball ache to work on I feel I should carry on with it as I know there's an accurate 12 ftlb gun in there somewhere.

Looking at making a spring compressor today I realised it was as much work to strip the gun to use a spring compressor as it is to strip to use the lathe, so for now I'll carry on without a compressor --- this will only become essential for final tweaking so can wait for now.


So the plan of attack for now is to strip the gun again.


Machine a bronze O ring piston head to take a Mercury sized ring --- on paper this will weigh 20.5 grams.

Fit a steel piston liner (plastic won't do) --- this could add another 10grams or more.

Initially sleeve the transfer port to 2.8mm --- this can be opened up if necessary.

Machine a new Spring guide from 316 stainless steel that actually fits the 10mm latchrod --- the original guide has a 12mm ID.

I'll carry on with the 28 coil Spring for now.

Run it over the chrono then either laugh or cry.

All up piston weight will be in the region of 300 grams with a 70-71mm stroke.

I measured up my ratting Mercury this afternoon and that is running a 69mm stroke with a piston weight of nearly 300grams so I should be in about the right pall park for 12 ftlbs with the D35.

If after a chrono session I need to alter piston weight and preload I'll be able to do all that from the backend without disturbing the piston as I'll have the 30gram piston weight with 16mm of preload to play with.


I'll keep you updated.





All the best Mick

[p.j.]

Watching with much interest. i picked up a 1977 Diana marked 35 in .177 recently, nice and clean to.
It will be featuring in AGW, so may be inclined to "steal" some ideas Mick.

[T 20]

Watching with much interest. i picked up a 1977 Diana marked 35 in .177 recently, nice and clean to.
It will be featuring in AGW, so may be inclined to "steal" some ideas Mick.

They're all fairly clean as most folks are too embarrassed to take them out and use them in public.

It's the only gun I can think of where the Spring guide forms an essential part of the trigger group.

The three ball trigger unit is basically a female Dowty coupling with the outer sleeve sprung loaded to release the male fitting rather than retain it.
The trigger sear holds the sleeve in the locked position --- pulling the trigger allows the sleeve to release under Spring pressure so firing the gun.




All the best Mick

[jonnyone]

Credit where its due you are giving this a good go. You deserve to have some good results on this. And I think those results will be invaluable to those who own these guns and who want to tease a little more performance from them. From my angle a 35 that has no more recoil than standard, is quieter than standard and most importantly is as accurate (or better still more accurate) than standard is a much desired outcome all in a package that is north of 11? Result! I await with genuine interest.
And when you think of it, those owners who own this gun in .177 have a bit more work than you to tease hunting power/accuracy from their guns. Wouldn't it be amazing if your recommendations also achieve optimum results for .177 also?

Keep it going.
Dave

[HW777]

Credit where its due you are giving this a good go. You deserve to have some good results on this. And I think those results will be invaluable to those who own these guns and who want to tease a little more performance from them. From my angle a 35 that has no more recoil than standard, is quieter than standard and most importantly is as accurate (or better still more accurate) than standard is a much desired outcome all in a package that is north of 11? Result! I await with genuine interest.
And when you think of it, those owners who own this gun in .177 have a bit more work than you to tease hunting power/accuracy from their guns. Wouldn't it be amazing if your recommendations also achieve optimum results for .177 also?

Keep it going.
Dave

While Mick likes a challenge Dave, I think the Diana 35 commemorative or the likes of, is a much better option for us mire mortals

[Adam77K]

They're all fairly clean as most folks are too embarrassed to take them out and use them in public.

It's the only gun I can think of where the Spring guide forms an essential part of the trigger group.

The three ball trigger unit is basically a female Dowty coupling with the outer sleeve sprung loaded to release the male fitting rather than retain it.
The trigger sear holds the sleeve in the locked position --- pulling the trigger allows the sleeve to release under Spring pressure so firing the gun.




All the best Mick

Thanks for the explanation. I’ve never owned one (and reading this thread isn’t selling them!) so had no idea how these triggers are supposed to work. That makes it really clear, cheers.

[Geezer]

Is it me, or is the D35 taking a bit of an unjustified kicking here?

It’s not perfect, but nor are pretty much any of the 50s/60s/70s sporters.

Webley Mk3, beautiful finish, questionable handling, heavy trigger. Don’t start me on the Hawk/Osprey.
HW35, porous breech, poor internal dimensions. Silly barrel on the “E”.
BSFs, punchy, but mediocre finish, trigger that self-adjusts to unsafe over time.
BSA Airsporter, some cheapy bits. Quite poor by the time of the Mk4/5.
Milbro Dianas…
Etc.

[crowbar]

I have done a few 3 ball triggers and I made a spring compresser from two pieces of 8mm allthread and two plates,
the front with a slot cut to drop over the breech block and the back tapped to take a long set screw with a spigot turned
on the end to mount the ballbearing cage .Just load everything up and screw it in simples .
You could make a spigot up and stick it in a chuck in the tailstock of your lathe .

I forgot to say make the spigot long enough to block the first hole but stop just short of the second as this wil line it up better and you
only need one pin to hold it to withdraw the spigot .

Had another thought I did one where the sear shuttle would stick now and then and it was riding up the radius of the guide/stop screw
in the slot on the bottom of the shuttle,I built it up with a blob of weld and filed it to suit .

[HW777]

Is it me, or is the D35 taking a bit of an unjustified kicking here?

It’s not perfect, but nor are pretty much any of the 50s/60s/70s sporters.

Webley Mk3, beautiful finish, questionable handling, heavy trigger. Don’t start me on the Hawk/Osprey.
HW35, porous breech, poor internal dimensions. Silly barrel on the “E”.
BSFs, punchy, but mediocre finish, trigger that self-adjusts to unsafe over time.
BSA Airsporter, some cheapy bits. Quite poor by the time of the Mk4/5.
Milbro Dianas…
Etc.

Any spring rifle that can not be serviced with nothing more than rudimentary tools, is an fail of the manufacturer to see the long term appeal of their product, the D35 is not a hidden gem more a embarrassment to the owner Hence why most remain in good condition.

Milbro Diana's should never have happened and Diana never forgave us for that one.

Had production gone to Webley or BSA we would have had some note worthy rifles to talk about and own

[T 20]

I have done a few 3 ball triggers and I made a threadcompresser from two pieces of 8mm allthread and two plates,
the front with a slot cut to drop over the breech block and the back tapped to take a long set screw with a spigot turned
on the end to mount the ballbearing cage .Just load everything up and screw it in simples .
You could make a spigot up and stick it in a chuck in the tailstock of your lathe .

I forgot to say make the spigot long enough to block the first hole but stop just short of the second as this wil line it up better and you
only need one pin to hold it to withdraw the spigot .

Cheers for that, Crowbar.

I'm actually using a bit of 10mm threaded rod with a nut on it to form the spigot in my lathe drill chuck to compress the ball cage to remove the front pin.
The rear pin seems to jump out on its own accord ever time I remove the action from the. Stock.

I may just cheat and buy a Sash clamp to convert into a spring compressor when I get to the fine tuning stage --- fitting a spigot as you describe, but I may use hardwood to the breech U to save the bluing.





All the best Mick

[Geezer]

Any spring rifle that can not be serviced with nothing more than rudimentary tools, is an fail of the manufacturer to see the long term appeal of their product, the D35 is not a hidden gem more a embarrassment to the owner Hence why most remain in good condition.

Milbro Diana's should never have happened and Diana never forgave us for that one.

Had production gone to Webley or BSA we would have had some note worthy rifles to talk about and own

The German concept of a a service was always that you would send it back to the factory for a service.

The British one was that you, a mate, or your local dealer would hit it with a hammer.

[T 20]

Is it me, or is the D35 taking a bit of an unjustified kicking here?

It’s not perfect, but nor are pretty much any of the 50s/60s/70s sporters.

Webley Mk3, beautiful finish, questionable handling, heavy trigger. Don’t start me on the Hawk/Osprey.
HW35, porous breech, poor internal dimensions. Silly barrel on the “E”.
BSFs, punchy, but mediocre finish, trigger that self-adjusts to unsafe over time.
BSA Airsporter, some cheapy bits. Quite poor by the time of the Mk4/5.
Milbro Dianas…
Etc.

There's the funny thing, Geezer.

When you look at the internal dimensions of the Original 35 it should have been up their with the best of them power wise --- it wasn't.
It had an excellent barrel and trigger for a sporting rifle of the time, but very little power to take advantage of that barrel and trigger --- even though it had a 12+ ftlbs potential swept volume.

The Original 35 and Original 50 should have walked all over the BSA Mercury and Airsporter but they didn't, even though they had a larger swept volume.

I'm just looking at why this is the case and attempting to upgrade my Original 35 into the gun I feel it should have been all along.




All the best Mick

[crowbar]

It's funny you should say that as my 1976 mod 27 is like that and it's only the slide on metal cap that keeps it in .
To remove the leather piston washer you will have to drill the screw out as it is pinned.

The breech lock up should clunk solid without a breech washer if it doesn't the pin is probably bent down a little due to being
fired with the barrel broke and the ball can't spring into location below it.

I forget what size the trigger balls are but they are a standard size for push bikes and can be had for a quid a bag not aquid each
from a spares place .

Another thing I found is the imperial cycle size and a metric ball is a close size but larger and they fit but will stick a bit and I had odd balls in one that did this to puzzle me.

[TonyL]

Is it me, or is the D35 taking a bit of an unjustified kicking here?

It’s not perfect, but nor are pretty much any of the 50s/60s/70s sporters.

Webley Mk3, beautiful finish, questionable handling, heavy trigger. Don’t start me on the Hawk/Osprey.
HW35, porous breech, poor internal dimensions. Silly barrel on the “E”.
BSFs, punchy, but mediocre finish, trigger that self-adjusts to unsafe over time.
BSA Airsporter, some cheapy bits. Quite poor by the time of the Mk4/5.
Milbro Dianas…
Etc.

Good point, Geezer. And, back then, many people probably wouldn't have been inclined to service / work on them themselves, negating the tricky-to-strip argument. As you say, many more sporting rifles of the era were flawed, the HW35 possibly being the best / most solid apart from the breech void on some. Even the much revered Anschutz 335 and FWB Sport weren't perfect.

[evert]

Good effort Mick, doing all this so we can follow.
Assembling the D35 hase never been my favorite job, but its not kept me from taking them apart to change springs, guides etc.
Sure, they a bit more fiddly than other guns, but what I really dislike is all the cutouts that will crape your seal if you dont deburr them,
which may be why I dont remember to have tried a synthetic seal in them?
And the trigger mechanism is a bit of a a pain.
My technique for assembly has just been pushing with a screwdriver shaft or something similar to get it together, and fiddling with punches to get all the holes to line up.