" Original " 75 the movie ..

[Steve Zodiac]

Hi Steve zodiac,
Could you tell me how to get these vidios up. I am just about to embark on the adventure myself .
BomarBob .

Just go on YouTube and put in " Diana 75 strip down " or such like and they should kick up.

The idea of learning the mechanical intricacies of these guns is really appealing, and for me a big part of the hobby, that said I have concluded that these are not the guns to start the learning process.

I've got two 75's one a universal that's clearly been apart before as the gear covers confirm with damage to the knurled part of the covers and some damage to one of the pin spanner holes.

The other Match 75 has never been apart, or if it has its been done with a high level of mechanical professionalism and skill.

I'm not about to bugger them up, so a professional rebuild is the sensible option for me.

I've also picked up a nice FWB 300 S this week , put about 200 pellets through it and really enjoyed shooting it, even if I've managed to shoot what looks like the original breech seal into a state of surrender.

I believe the new seals have moved on since the birth of these guns so they should last a long time, just as well as mine will be getting lots of exercise in my new cellar 8 meter range.

[dvd]

When I opened up a Giss type Diana for the first time, I remember I was more weary of tools slipping and marring the bluing or knurling than anything else. So I set about making specific tools and kept reminding myself that there are no short-cuts with this gun. The end cap and some gear wheel covers have pin-spanner holes, but if they have never been undone before, they will be hard to undo and risk damage. I found that curved jaw locking pliers and thick leather as padding was the way to go. A spring compressor is a must.
The Diana 75 is the most involving of all the Giss types since it has also an anti bear trap mechanism to contend with.
Perhaps opening up a less complicated model such as the Mod 60 target gun or a Mod 6 pistol is the best way how to "get it".

[Steve Zodiac]

When I opened up a Giss type Diana for the first time, I remember I was more weary of tools slipping and marring the bluing or knurling than anything else. So I set about making specific tools and kept reminding myself that there are no short-cuts with this gun. The end cap and some gear wheel covers have pin-spanner holes, but if they have never been undone before, they will be hard to undo and risk damage. I found that curved jaw locking pliers and thick leather as padding was the way to go. A spring compressor is a must.
The Diana 75 is the most involving of all the Giss types since it has also an anti bear trap mechanism to contend with.
Perhaps opening up a less complicated model such as the Mod 60 target gun or a Mod 6 pistol is the best way how to "get it".

That's exactly why I won't be attempting my 75's

Especially those little gear covers need the right tools and knowledge to do the job properly. I'd make them look like a blind man with boxing gloves on did the rebuild..

I could, given the right tools and a methodical gentle approach have a good go, but id rather it was done properly by a pro.

There's always little do's and don'ts to get the job done properly so the gun shoots as well as it can and lasts the test of time.

Something as simple as correct lubrication or no lubrication at all can make all the difference.

I want to try and do myself justice shooting these target rifles so its important they work as intended or I'm never going to improve the skill of shooting accurately .

I think if I could get my hands on a low value 75 for repair I might be tempted to have a go myself.

The major problem is the breech seal availability or lack there of at the moment.

[dvd]

That's exactly why I won't be attempting my 75's

Especially those little gear covers need the right tools and knowledge to do the job properly. I'd make them look like a blind man with boxing gloves on did the rebuild..

I could, given the right tools and a methodical gentle approach have a good go, but id rather it was done properly by a pro.

There's always little do's and don'ts to get the job done properly so the gun shoots as well as it can and lasts the test of time.

Something as simple as correct lubrication or no lubrication at all can make all the difference.

I want to try and do myself justice shooting these target rifles so its important they work as intended or I'm never going to improve the skill of shooting accurately .

I think if I could get my hands on a low value 75 for repair I might be tempted to have a go myself.

The major problem is the breech seal availability or lack there of at the moment.

I think breech seals can be fabricated fairly easily if you cant find any, however they have to be correctly sized since the closure of the cocking lever as it squeezes the cylinder seal against the barrel is critical because it affects the trigger operation. I would be more worried about damaged pistons and cog-wheel cover threads on the cylinder, since these are very expensive to replace. Steer clear of these damaged guns as repair is very very expensive.
I got my 2 mod 75's with defective seals, but the previous owners had assured me that the guns cocked and fired. That way I knew that no mechanical issues were present. The springs in these guns last for ever.

[Steve Zodiac]

I think breech seals can be fabricated fairly easily if you cant find any, however they have to be correctly sized since the closure of the cocking lever as it squeezes the cylinder seal against the barrel is critical because it affects the trigger operation. I would be more worried about damaged pistons and cog-wheel cover threads on the cylinder, since these are very expensive to replace. Steer clear of these damaged guns as repair is very very expensive.
I got my 2 mod 75's with defective seals, but the previous owners had assured me that the guns cocked and fired. That way I knew that no mechanical issues were present. The springs in these guns last for ever.

I wish someone would fabricate a few then

What's the material used ? I thought it was maybe unobtainium ?

Both my guns are shooting ok , one is a bit down on power but the tissue test doesn't show any puff escaping from the breech area on either 75.

I just feel they need servicing purely based on the time thing. I'd hate for them to fail epically

I'm putting about 20/50 pellets through most evenings in my quest for improving my skills.

[dvd]

I wish someone would fabricate a few then

What's the material used ? I thought it was maybe unobtainium ?

Both my guns are shooting ok , one is a bit down on power but the tissue test doesn't show any puff escaping from the breech area on either 75.

I just feel they need servicing purely based on the time thing. I'd hate for them to fail epically

I'm putting about 20/50 pellets through most evenings in my quest for improving my skills.

The seals are made of some synthetic material, very similar to what is commonly used in most guns, so no problems in sourcing them.
I buy my parts from Waffen Gotha in Germany, good people to deal with and good prices too. They do a complete overhaul kit for the Mod 75.
When the velocity starts to fall off below 400 fps, it is time to renew the seals with the modern blue ones. Do not go on shooting the gun in this state because the deterioration of the seal effectively alters the timing of the pistons and you risk damaging the pistons and gears.
Otherwise with new seals in place, they are good to go for many many years.

[Steve Zodiac]

The seals are made of some synthetic material, very similar to what is commonly used in most guns, so no problems in sourcing them.
I buy my parts from Waffen Gotha in Germany, good people to deal with and good prices too. They do a complete overhaul kit for the Mod 75.
When the velocity starts to fall off below 400 fps, it is time to renew the seals with the modern blue ones. Do not go on shooting the gun in this state because the deterioration of the seal effectively alters the timing of the pistons and you risk damaging the pistons and gears.
Otherwise with new seals in place, they are good to go for many many years.

This is all nappy filling stuff!

I'm going to stop shooting them until they're sorted.

My breech seals look like a very worn out versions of the pictured " luftdichtung " in the service kits on the Waffen Gotha site. I assume the breech seal in the photo is the old material ie not blue ? I'd guess the breech seal can be changed any time without stripping the gun so anything is better than nothing. Tom will be servicing my guns at the Air gun clinic local to me. He knows his onions so I'll liaise with him on the best route to take.

Shame my FWB 300 S breech seal failed the other day ( its in two halves ) .


Edit ; I've had an idea !!

I wonder if it would be possible to turn out some breech seals ( blue ) using either the piston or buffer seals as donors ?

Is there enough meat to pop it on a lathe if the dimensions were taken from the Diane breech seal ?

Just a thought.