Any engineers know why the metal dangerously failed on DIana trigger

[bighit]

and just because chambers has none left does not mean they have sold "loads" of the parts involved.

they may only have carried 1 or 2 of most parts as stock level.

[Barryg]

and just because chambers has none left does not mean they have sold "loads" of the parts involved.

they may only have carried 1 or 2 of most parts as stock level.

What I said was

(Is there anyone friendly enough with chambers to find out how many of these parts have been sold over the last five years?)

I am guessing that Chambers keep records for past year's, even then there could be another expiation other than a broken part but be interesting

[Rickenbacker]

To be honest, if I hadn't have seen this thread then I probably wouldn't have even mentioned what had happened, because of what I did slamming the barrel shut more fiercely than normal, could that have been classed as "rough handling" which could have caused the failure or could it have even been classed as some form of "drop test" which we all know all guns have to go through to be classed as safe (didn't Walther have this problem with the LGV in it's early days?) but because my gun went off due to mechanical failure and not a design fault or adjustment issue, is it classed as the same thing, [...]

I been thinking about this Pete, it doesn't sound like anything you've done - unless there's some reason why the action of swinging the barrel shut could have been pulling forward on the piston...

Was there possibly a mismatch of parts? I notice the '45 cocking arm (and barrel) have different part numbers to the 34 series... could your combination of parts have resulted in a shorter throw to the cocking arm?

[bighit]

What I said was

(Is there anyone friendly enough with chambers to find out how many of these parts have been sold over the last five years?)

I am guessing that Chambers keep records for past year's, even then there could be another expiation other than a broken part but be interesting

why not ask your self then?

and they could have been sold for any number of reasons other than breaking. for example a shed tuner buying a spare one in case his home tuning and polishing of the sear went wrong.

[look no hands]

I been thinking about this Pete, it doesn't sound like anything you've done - unless there's some reason why the action of swinging the barrel shut could have been pulling forward on the piston...

Was there possibly a mismatch of parts? I notice the '45 cocking arm (and barrel) have different part numbers to the 34 series... could your combination of parts have resulted in a shorter throw to the cocking arm?

You're right about the different cocking arms but I used the 34's arm on the 45 breech block, not sure if the hole in the 45's breech block that the linkage pin goes into is slightly more forward than the 34's which could have caused the cocking arm to pull the piston off the sear, I'll have to have a look.

The new sear turned up today from Chambers, I took a few photo's but because our camera is crap I just can't get a decent clear close up of the broken sear.

Pete

[edbear2]

Shame that the pictures don't show the fracture faces, but my first thought is the lack of a radius in the corner where the crack appears to have initiated. There will be a high stress concentration in that area, and sharp corners don't get on well under high stress loads. Look up Liberty ships in WW2 and the original Comet aircraft design.
The part will obviously need to be hardened to stop the sear face wearing away, so any breakage on components of this type will be a brittle fracture.
Putting it bluntly, it's a design fault...

The radius thing mentioned was the first thing I noticed too!

ATB, ED

[Barryg]

I suppose it could be just a just small batch of defect parts as if the design was faulty how could the older T06 trigger's take this kind of cranking up and never hear of a breakage
http://www.network54.com/Forum/18447...Vortek+wire%29

[westy306]

Post up a clear macro picture of both break faces please.

I can ask one of the metallurgy experts at work.

[look no hands]

Post up a clear macro picture of both break faces please.

I can ask one of the metallurgy experts at work.

You won't get one from me as I can't even get the damn thing in focus with our crappy camera.

Pete