Tuesday, May 13, 2008

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.
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.


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.


richard said...

brilliant article...now i can rebuild my m 6 i purchased 2 days before the birth of my son [ nov 3rd 1980 ] as i was in withdraw from the pistol range...the guns seal/s were blown by a man i befriended, and stole it while i was at work [1984 ]. ended up at a pawn shop and cost me $25.00 to get it back...lucky , i felt
it has been in storage since 1985...i am now back into air guns because ammo prices, soared as supply declined....
again nick, thank you for your great job...
as soon as i get seals in my hand i will start my rebuild...
i have recently purchased a fine 177 pistol, that had no power ... has absolutely no markings...none...
it is a spring gun, break barrel, and upon breaking it down i found all that was wrong was the leather seal had dried out..i used lanolin after cleaning the chamber with acetone...post assembly, resulted good groups but i had to raise the front sight by adding a wedged style pencil eraser to put it in the bull and it groups well, plus has good power when i shoot a softdrink can at 45 feet...it shoots almost as well as the m6 did , which pleasantly shocked me me... for the change i have invested in the spring pistol...i plan on making a new front sight, as the rear is fine with it's windage and elevation working well...i will give it to my grandson when he is of age and can be taught gun safety [ 3 1/2 years ] although i am teaching him bb rifle at 20 feet, prone with sand bag at tin cans, with eye protection
again,nick, a sincere thank you !

lake texoma , texas
texas side
sorry for thr lower case, but have issues since being run down on my bmw paris-dakar in 2006 while on tour of arizona and new mexico

Anonymous said...

Hi i am Horst from Germany. IGot an 1970 M6 Today. With Your help i was able to disassemble it. I immediately ordered new seals.


PLUNKER said...

With your help, I'm rebuilding a Model 6M, that I purchased new in 1986. The three folders that came with this gun have conflicting maintenance instructions. One has pictures of all of their guns and instructs that "A few drops of RWS compression chamber lube every 500 shots will suffice". The second, with a picture of the 6G inside, says "A few drops of RWS compression chamber lube every 2500 shots will suffice". And the third, which says MODEL 6M on the cover and has pictures of this gun inside says "As the compression tube and piston are made of a new kind of material they need absolutely no attention, and must not be oiled!". Intrestingly, I had only oiled the front chamber, not fully understanding the internal design, and, upon disassembly, found the front seal to be disintegrated and the real seal completely intact. My question is: If you're not going to ever oil this gun, what lubrication would you use to assemble the pistons into the chamber?
Since it's been a few years, since your original post, I hope you're still around and doing well.

Olive Branch, MS

Nick Carter said...

You want really light moly on the piston, Derrick and I seem to use the Slick Honey grease on many other parts, but pretty light. Not a fan of oiling chambers especially with silicone based oils.

Miguel said...

Thanks for your post picked up one a swap meet 25$ in it carrying case good shap minus sights..and no compression...yr post will help me alot thankdld