Resurrecting A Diana Model 6M Pistol, Part 2

And on we go...

The pivot and pivot lockscrews.

It's a good idea to break the action slightly to relieve stress on the pivot from the ball detent.

Hmmm, nice pivot washers.

Shiny!

One pair of washers (one of which is a spring washer?) and one washer for the other side.

Removing the pinion cap screws.

I should note at this point that every single assembly of parts I removed got its own ziplock baggie. This was a great help in remembering what goes where, and those screws are tiny!

Normally this is where I make a special tool, but the instructions said the tang of a file could be used, so that's what I used...A slight amount of spring tension was taken up with the spring compressor.

And the left hand (with the action upside down in the compressor) pinion cap was removed, revealing the pinion gear. I fished it out with a dental pick.

I can't tell you how happy I was to not see any broken gear teeth.

At this point the file is pressing slightly forward.

And then turned to rotate the rear piston away from the right hand pinion.

And then the rear piston is removed along with the springs.

The other pinion, similarly intact!

The front piston is removed. But I think I need a new front seal...

Notice the spring guide, shown assembled into the piston.

An empty action...

I fished the rear piston washer/spacer out of the cap.

It has a hole through it.

The two parts cemented together from age and pressure. Notice the small step on the right. This is important later. The washer was stamped ".8" which is the thickness of that stepped section.

An Xacto knife removed the seal/washer/thingy from the metal spacer washer.

Finally the sight was dismantled. First the c clip is removed.

Then the washer.

And the windage screw, um, unscrewed.

There is a tiny ball bearing that goes where the arrow is pointing. I did manage to preserve it, just forgot to take a picture...

The rear sight unit was pulled out of the body.

Then the metal housing with the windage scale and spring were pulled out.

After this I spent a day or two cleaning every part...it was a pain and a half. There was grit and grease and decomposed seals. I used 5 pipe cleaners, a roll of paper towels, copious WD-40, soap and water, steel wool and a toothbrush.

More to follow in a day or so...

Resurrecting A Diana Model 6M Pistol, Part 1

What can I say, I have a masochistic streak. So when I found this Diana Model 6 M pistol for sale on Gunbroker I knew I had to buy it.
"THIS PISTOL HAS SOME FIRE DAMAGE TO PLASTIC STOCKS AND BARREL SHROUD.IT COCKS AND FIRES BUT AT SOME TIME HAS BEEN NEAR HEAT.THERE IS SOME BLUEING AND PAINT LOSS."
He wasn't kidding...

I've always been fascinated by the Giss contra piston recoiless action but didn't want to learn on and possibly destroy a better quality airgun. I received the pistol in exactly the sort of condition I expected (although the seller also shipped the gun with the action "broken" which is a really bad idea). I prepared by buying a new set of seals from James Maccari and hunting up any references to rebuilding I could find. I found an excellent guide in one of the forum archives which guided me through the disassembly and resealing without a hitch, although I had to do a far more extensive teardown and cleaning than the article covers.

The pistol.

Doesn't look too bad?

The grips are melted and partially bubbled...

The barrel shroud is similarly damaged.

RWS MOD 6 M

First up was removing the rear sight.

Doh! I turned the elevation screw and it snapped right off.

Stupid plastic. It's a left hand metric thread, but more on that later...

Well, now to remove the two screws and remove the sight.

The beautiful variable width front sight.

I removed the screws and had to drift the sight out of the dovetail.

I loosened this screw which caused the shroud to shoot forward, and bind the screw...

I should have removed this setscrew first, which releases the spring tension on the shroud locking mechanism. No problem, got it all apart and slid the shroud off the barrel.

Removing one grip frame screw

And the other grip frame screw.

Now what?

Remove the end cap screw.

A strap wrench removed the end cap. I was prepared to use pump pliers, luckily it didn't come to that...

The end cap, spacer washer and for lack of a better term recoil washer seal thingy...

The rear piston looked ok. just a tad dirty?

I removed the trigger catch arm spring.

Then the trigger catch arm.

I drifted the trigger pivot pin out.

This is a helpful picture.

The instructions said "punch out the cocking lever pin 6 (this is a loose fit so a punch is not needed)." This was untrue. My pin had a knurled center section and was quite tight and required considerable persuasion.

The cocking lever arm was pushed forward in the slot and removed.