I am concerned about some Diana T06 pistons (A bit scary)

[lensman57]

This is just bad design and engineering. The pressure of the FAC rated spring acting longitudinally on a rod that is keeping the piston from firing by simple fluting ( alomg the same direction as the acting force ) and crimping. Surprised from the Germans.

A.G

[look no hands]

Holy crap, that looks scarey! Aren't those huge crimps on the piston front supposed to hold it in, or what keeps it from flying apart? If that happened with the rifle cocked it would fire without the trigger being pressed, extremely dangerous.

No the huge crimps just hold the front of the piston (basically where the seal mounts on) onto the cylinder, the only time I've seen a wobbly piston rod was on my XS208 but you wouldn't be too surprised with that as it's a cheap Chinese copy, I replaced the whole thing with a T06 conversion kit, certainly makes you wonder, I'm a little worried now as I had the T06 trigger sear break on me last year.

May be what Diana need to do is what Air Arms do and thread the end of the rod and Loctite it into the piston seal carrier, I'm sure I read recently that the new pistons where better made since they have been taken over, it was something to do with the crimping and the issue of them being out of round?

It still seams that the good old loading tap or rotary breech system is still the safest design, thinking about it I've never had any issues with the rods on any of my Mercs/'sporters and they are a very old design and I admit they are not always the best of quality built (pistons being made out of rolled metal sheet for example).

I probably shouldn't say this but Tony Wall at SFS once told me that someone from one of the shooting mags once went to the Diana factory and was allowed to go around the factory on his own, when he got to the testing department, the QC guy shot a rifle and it was all over the place and it was then put in the "PASS" rack, when the mag guy looked closer at the rifle, the barrel was bent (or something like that), he was shocked at what he saw and went and complained but that rifle still stayed in the "PASS" rack and nothing was done about it (not sure if any of that is true but it's what I was told).

I still stand by what I say about German products (be it whatever), people seem to think that everything that comes out of Germany is the best quality and engineered but it's far from the truth.

Pete

[Hsing-ee]

No the huge crimps just hold the front of the piston (basically where the seal mounts on) onto the cylinder, the only time I've seen a wobbly piston rod was on my XS208 but you wouldn't be too surprised with that as it's a cheap Chinese copy, I replaced the whole thing with a T06 conversion kit, certainly makes you wonder, I'm a little worried now as I had the T06 trigger sear break on me last year.

May be what Diana need to do is what Air Arms do and thread the end of the rod and Loctite it into the piston seal carrier, I'm sure I read recently that the new pistons where better made since they have been taken over, it was something to do with the crimping and the issue of them being out of round?

I still stand by what I say about German products (be it whatever), people seem to think that everything that comes out of Germany is the best quality and engineered but it's far from the truth.

Pete

Is the piston rod just held in the piston by those splines? It CAN'T just be a friction fit, that would be insane. Certainly any other maker would thread the rod and screw it in tight with locking agent like you say.

The German thing is right, I have had poor finishing on Weihrauchs of all generations, not all of them but certainly one in four or so on average, or 100% in the case of the HW30. One HW30 had a cocking slot that was cut out of parallel with the cylinder! Air Arms does not seem to have this QC problem, although they always need relubing.

The only springers which really do (or did) not need attention and which were perfect out of the box were the old 10 meter match rifles. Models like the Feinwerkbau 150/300 series, the Anschutz 380 and the Original 75 were built up to a standard and not down to a price. Also, they were sold to shooters who could really shoot and knew their onions, and who would spot imperfections on the first few shots. They could not get away with 'extended breaking in periods' while the grinding surfaces smoothed out - there is a blog somewhere with an American HW99S owner using both hands on the barrel to cock the rifle while the galling sorted itself out!

BSAs for the most part seem to be well made, but the designs are less than they should be, always working on the 'good enough' rather than 'best' principle and that business of the Maxigrip and the 13.8mm scope rail! oh my lord. I will try to get hold of a SuperStar at some point for my collection and maybe a Cadet... it is a shame as some BSAs are inspired, like the Buccaneer and the RB2 but they never executed the designs quite right. If you want a good example of how they could have been done, compare a Mk 2 Airsporter with a German Falke 80, which is a copy of it. The Falke has the precise trigger the Airsporter lacks and it exudes top-level quality. BSA could have been Air Arms, but lacked the confidence or the clarity needed. They did make some awful rifles as well, like the BSA Merlin, now that is a POS, and I had a go with a gasram break barrel (a Super Shit?)a couple of years ago that was worse than any SMK I have tried, awful trigger and grouped like a cylinder-bore shottie.

[Barryg]

It seems it's a T06 problem,if anyone knows of the older pistons separating please post details.

Also it seems only the fixed barrel pistons.

When there is no fault these pistons take a lot of pressure just look at the vortek springs the Americans fit in them

[look no hands]

It seems it's a T06 problem,if anyone knows of the older pistons separating please post details.

Also it seems only the fixed barrel pistons.

When there is no fault these pistons take a lot of pressure just look at the vortek springs the Americans fit in them

Barry did you ever hear anymore about the T06 sear breaking problem from last year?

I had my 34 apart last weekend and the rod seemed pretty sturdy, so hopefully, like you say it's just the sidelever pistons causing the problems.

Pete

[look no hands]

Is the piston rod just held in the piston by those splines? It CAN'T just be a friction fit, that would be insane. Certainly any other maker would thread the rod and screw it in tight with locking agent like you say.

The German thing is right, I have had poor finishing on Weihrauchs of all generations, not all of them but certainly one in four or so on average, or 100% in the case of the HW30. One HW30 had a cocking slot that was cut out of parallel with the cylinder! Air Arms does not seem to have this QC problem, although they always need relubing.

The only springers which really do (or did) not need attention and which were perfect out of the box were the old 10 meter match rifles. Models like the Feinwerkbau 150/300 series, the Anschutz 380 and the Original 75 were built up to a standard and not down to a price. Also, they were sold to shooters who could really shoot and knew their onions, and who would spot imperfections on the first few shots. They could not get away with 'extended breaking in periods' while the grinding surfaces smoothed out - there is a blog somewhere with an American HW99S owner using both hands on the barrel to cock the rifle while the galling sorted itself out!

BSAs for the most part seem to be well made, but the designs are less than they should be, always working on the 'good enough' rather than 'best' principle and that business of the Maxigrip and the 13.8mm scope rail! oh my lord. I will try to get hold of a SuperStar at some point for my collection and maybe a Cadet... it is a shame as some BSAs are inspired, like the Buccaneer and the RB2 but they never executed the designs quite right. If you want a good example of how they could have been done, compare a Mk 2 Airsporter with a German Falke 80, which is a copy of it. The Falke has the precise trigger the Airsporter lacks and it exudes top-level quality. BSA could have been Air Arms, but lacked the confidence or the clarity needed. They did make some awful rifles as well, like the BSA Merlin, now that is a POS, and I had a go with a gasram break barrel (a Super Shit?)a couple of years ago that was worse than any SMK I have tried, awful trigger and grouped like a cylinder-bore shottie.

Like you say, I remember when I did a bit of 10m shooting in the mid 80's and the Walther sidelevers we used back then where pretty damn bombproof and oozed quality even though they had seen some action and abuse.

BSA also lacked the funding from Gamo, they always seemed to drop the good rifles for the crappier ones and then build them down, they've gone for the Poundland approach, they've not made anything decent since the Superstars and RB2's etc I'm afraid to say.

Pete

[bighit]

The only Diana I've ever opened up was a 20 year old 48. The piston rod wobbled around freely, but didn't pull out. I assume it was just about ready to let go. At least the bear trap would save your fingers/thumb.

It will save your fingers or thumbs when cocking but if the piston latch road breaks free from the piston , no safety catch or bear trap will stop it firing after its been cocked will it ?

You could be walking in the fields with a rifle that could go off any second with the safety ON or be in your own yard.

Yes I know safety's don't always work but I'd rather trust my safety than a rifle that could have a latch rod that comes out the piston at any time when coked. Wouldn't you ?

[bighit]

Piston rods being https://www.gatewaytoairguns.org/GTA...?topic=49571.0
There are others saying the same thing but I'm on my phone and linking to pages is a PITA.

Some are saying they can't cock the rifles as the end of the latch rod is hitting the spring guide.

[flyingfish]

I have only ever owned a k98, this came with ATB

[NickG]

Yep, I did have a brief dalliance with Diana rifles, but you are right. They're shit.

Second that

[Black Beard]

Yep, I did have a brief dalliance with Diana rifles, but you are right. They're shit.

Didn't I buy one from you? :-)

[bighit]

http://www.network54.com/Forum/18447...se+piston+stem

I liked this comment from the above thread

this has been going on for years and they are shocked? April 11 2012, 6:38 AM

what a crock of doo doo.

[junglie]

I've had the piston head seperate from the piston on an old bsf s70, the spot welds holding it on failed. Why diana couldn't use a pin through the rod & head like bsa is my question though?

[Barryg]

http://www.network54.com/Forum/18447...se+piston+stem

I liked this comment from the above thread

this has been going on for years and they are shocked? April 11 2012, 6:38 AM

what a crock of doo doo.

I had forget that interesting thread

Although I could remember some of the comments that Hector made about the pistons being safe if the stem is tight in the head, it seems that only the later T06 pistons actually separate dangerously even though the body's have been loose for years.

Anyone think that the factory pistons could be modified or would it be more simple to just get a custom piston?

[flyingfish]

Didn't I buy one from you? :-)

I sold one to him