Picked up first Gen. Diana 34 ** TUNED & NEW CHRONO NUMBERS **

[GoldenStateAIRGUNer]

Bought this on Ebay and came with a Hawke Sport HD 3-9X40mm scope. Both look nearly new. Gun is dated 05 84. Started to tear into it as I'm going to tune it. Probably will sell when done. Didn't the 34 use two different piston seal diameter based on manufacture date ? I'm not going to pull the spring out until I get some 5mm x 24mm cabinet pins to hold the trigger mechanisms in place. Some pics.

 

[GoldenStateAIRGUNer]

Should have mentioned. Chronographed @ 839 fps with 8.44 (4.53mm) JSB's.

 

[Lewis]

Great find. Well done

 

[GoldenStateAIRGUNer]

I just haven't seen any of these before. Seems sorta rare !

 

[Glenroiland]

Sweet! As usual...I am envious!!

 

[Moog]

looks nice. How does the quality compare to the current ones?

 

[GoldenStateAIRGUNer]

looks nice. How does the quality compare to the current ones?

It's nice. Even the cap over the trigger end of the tube is steel. Trigger is the weak spot.

 

[GoldenStateAIRGUNer]

Well, I used my Air Venturi spring compressor for the first time. Worked great! Spring was pretty dry as well as the guide. Piston seal (also dry) was original Diana 28mm. Notice the damage (crushed flat spot) on the piston seal. I have a new Vortek M28 Moly impregnated one coming as well as a new breech seal coming from Umarex. Umarex is sending it free of charge. It's going to be a snug fit getting that piston in the receiver tube without damaging the seal. I know member Seven08 (Bob) said he used a plastic piece of milk bottle to sheave the piston seal. I'm probably going with something thinner like a plastic soda bottle. Anyone try this or I'm open to other ideas ?

 

[thumper]

That's a real clean ole gun! I like it. 

A new seal that ain't all messed up and some good moly will have her fixed right up. Bet it will be a great shooter. 

 

[Pea-shooter O.G.]

That sure is a nice unit. I have used a piece of camera film to protect the piston seals when sliding them past the sharp cut out edges. 

 

[Guest]

I borrowed your picture and circled but hardest place for me getting a new seal back in is the corners on the U shaped cut out. Easiest trick I've found so far is slide the piston/seal in to just before that point, slide an .006 or .007 feeler gauge between those points and the seal, then push the new seal past. 

 

[GoldenStateAIRGUNer]

That sure is a nice unit. I have used a piece of camera film to protect the piston seals when sliding them past the sharp cut out edges.

Good idea ! It's got to be thin that's for sure.

 

[GoldenStateAIRGUNer]

I borrowed your picture and circled but hardest place for me getting a new seal back in is the corners on the U shaped cut out. Easiest trick I've found so far is slide the piston/seal in to just before that point, slide an .006 or .007 feeler gauge between those points and the seal, then push the new seal past. 

Good idea as well! The leading edge is also kind of sharp. All the places where the 90 deg angles are are also hazards. 

 

[Pea-shooter O.G.]

Don't overlook the opening of the cocking slot also! 

 

[Moog]

How about working those sharp edges with some fine grit sand paper?

 

[GoldenStateAIRGUNer]

Thought of it but don't like the idea of sanding through the bluing.

 

[Guest]

Feeler gauge set from Harbor Freight, $6 or $7? They can be spread thanks to the holder and used one handed if you want to use more than one and would cover the all the points on the back end. Those are the ones that tended to leave gouges in my seals if I screwed up and what made me think of trying feeler gauges.

You can see I use the .006...lol.

 

[GoldenStateAIRGUNer]

Good idea ! I think I have a set like that. I am going slightly bevel and polish that leading edge just to get the seal started in the the receivers bore. I might try and polish those 90 deg points as well. 

Also, inside the piston is a plastic sleeve. I'm assuming that's a spring guide within the piston and may also dampen spring twang/vibration?? Is that removable or not ?

 

[GoldenStateAIRGUNer]

Spend over an hour deburing and polishing the receiver tube. Bought a Dremel tool which included polishing compound and rubber polishing bit. I'm in no hurry on this project. Also polished the trigger block retainer holes in the tube. They had some edges on them.

 

[Guest]

Also, inside the piston is a plastic sleeve. I'm assuming that's a spring guide within the piston and may also dampen spring twang/vibration?? Is that removable or not ?

That part I honestly have no idea. I have an older D34 .177, but mine is a 2002 version and I've never had it apart. Maybe try shooting Motorhead a PM and see what he says??