Burst Test of the new Light Weight M-Rod air tube from JSA

[avator]

Thanks Lloyd... I'll be grabbing one for the Gen2 w/gauge hole as well. I fill from my 3300psi scuba tanks so I'll probably not be concerned with safety anyhow.
My only complaint with my synrod was weight. That's what has kept it restricted to the shooting bench. Hopefully the 1 1/2 pounds will bring the gun within the limits of my bum shoulder.

[lloyd-ss]

are the steel tubes able to go up to even higher pressures even?  I have wondered how much of a safety factor guns like the huben have where they are filling to 4500 or are we pushing the metals more than should be done.

I tested a steel tube I made for the Discovery. Same size as a Disco tube: 7/8" O.D. x .065" wall. It was A513Type5 DOM mild steel welded hydraulic  tubing. Same 13/16-28 threads in the end as the disco. I threaded and plugged both ends because I knew the valve screws would break long before the tube. Anyway, that tube split open at 16,000 psi, so the material is capable of the task. Hopefully, the design is up to the task, too, and you have to trust the manufacturer on that. Like I stated in the first post in this thread, there are a multitude of ways the pressure system can fail, and they all need to be addressed.

[lloyd-ss]

Thanks Lloyd... I'll be grabbing one for the Gen2 w/gauge hole as well. I fill from my 3300psi scuba tanks so I'll probably not be concerned with safety anyhow.
My only complaint with my synrod was weight. That's what has kept it restricted to the shooting bench. Hopefully the 1 1/2 pounds will bring the gun within the limits of my bum shoulder.

Shoulder your gun and imagine setting two full 12 oz cans of soda on top of it. Then toss the cans off. That is the difference in weight. Nice!

[FuzzyGrub]

But back to the diameter measurements.
Started at 1.245" dia.
At 9,000 psi dia was about 1.249".
Dropped pressure to zero, and dia measured 1.247".
Raised pressure to 10,000 psi and dia was about 1.300".
Dropped pressure back to zero, and dia returned to about 1.280-1.290"

I find that interesting ,

So it permanently deformed by taking it to its limits.  I would expect that taking it to just 3k, it may expand slightly, but should return to the original at zero, within measuring capability.  Would that be correct? 

[lloyd-ss]

But back to the diameter measurements.
Started at 1.245" dia.
At 9,000 psi dia was about 1.249".
Dropped pressure to zero, and dia measured 1.247".
Raised pressure to 10,000 psi and dia was about 1.300".
Dropped pressure back to zero, and dia returned to about 1.280-1.290"

I find that interesting ,

So it permanently deformed by taking it to its limits.  I would expect that taking it to just 3k, it may expand slightly, but should return to the original at zero, within measuring capability.  Would that be correct? 

You are correct, it would expand very slightly (less than one thou), but would return to its original size. Permanent deformation starts at something over 8,000 psi. Think of stretching the elastic in your shorts. Pull it a little and it returns to original size. Pull it till you hear the snappy noises (yield point), and you've messed up.

[FuzzyGrub]

I understand the sample of one and other factors.  From JSA mfg side, I would think the quality and depth of the threads for the fill assy, to be one of the more critical items to check on each tube.   I'd expect that if there was any valve screw hole size or position issue, that could be detected by the user. 

[avator]

A bit off topic and I apologize but.... is there also a lighter weight barrel shroud available?

[FuzzyGrub]

A bit off topic and I apologize but.... is there also a lighter weight barrel shroud available?

Its already aluminum and think it only weighs around 4-5oz. 

[avator]

K, thanks John.

[wimpanzee]

Does this mean that the aluminum anodized shroud will actually match the tube now? I dunno about anyone else, but my (original) tube is black, and the shroud is like a very very dark purple in full sunlight.

[mobilemail]

I was concerned about fatigue, and I'm glad that the question came up and Lloyd addressed it.  I appreciate the JS team working hard to prove and openly demonstrate the quality of this aftermarket part, that is really what sells it for me. 

And I respect Lloyd's input because I believe he respects the potential dangers of HPA enough that I don't think he could sleep at night if it was misrepresented.

So...I got in on the gen1 pre-order.  My favorite squirrel hunting rifle is going to be a little more bearable scrambling up the hills. 

[avator]

Yep, just have to get the accounting department to release the funds.

[Dairyboy]

A bit off topic and I apologize but.... is there also a lighter weight barrel shroud available?

I don't believe you can make it much lighter. There pretty light as they are. I guess taking it off would make it lighter 

[lloyd-ss]

I was concerned about fatigue, and I'm glad that the question came up and Lloyd addressed it.  I appreciate the JS team working hard to prove and openly demonstrate the quality of this aftermarket part, that is really what sells it for me. 

And I respect Lloyd's input because I believe he respects the potential dangers of HPA enough that I don't think he could sleep at night if it was misrepresented.

Thank you for the kind words, Mark. Even though my tests and opinions are offered for information only, I do take the safety aspect extremely seriously. The airgun parts should be such that I would be comfortable watching my grand kids use them. No exceptions.

Now, for my own personal stuff, I might bend the rules a tiny bit if there is a good reason to do so, and still remain safe.

[avator]

I was concerned about fatigue, and I'm glad that the question came up and Lloyd addressed it.  I appreciate the JS team working hard to prove and openly demonstrate the quality of this aftermarket part, that is really what sells it for me. 

And I respect Lloyd's input because I believe he respects the potential dangers of HPA enough that I don't think he could sleep at night if it was misrepresented.

Thank you for the kind words, Mark. Even though my tests and opinions are offered for information only, I do take the safety aspect extremely seriously. The airgun parts should be such that I would be comfortable watching my grand kids use them. No exceptions.

Now, for my own personal stuff, I might bend the rules a tiny bit if there is a good reason to do so, and still remain safe.

LOL.... Careful Lloyd... you know Bob Sterne is watching.

[moorepower]

I was concerned about fatigue, and I'm glad that the question came up and Lloyd addressed it.  I appreciate the JS team working hard to prove and openly demonstrate the quality of this aftermarket part, that is really what sells it for me. 

And I respect Lloyd's input because I believe he respects the potential dangers of HPA enough that I don't think he could sleep at night if it was misrepresented.

So...I got in on the gen1 pre-order.  My favorite squirrel hunting rifle is going to be a little more bearable scrambling up the hills. 

If I am not mistaken fatigue tests on an air tube such as this would be done 0 to 3000 psi not 2000-3000 psi, which no one does on a gun that is not leaking. Most of us don't shock the tube with an instant 3000psi either.

[Dairyboy]

I get mine today!!

[squirrel_hunter]

I get mine today!!

mine also and a package from USPS...

[Dairyboy]

I get mine today!!

mine also and a package from USPS...

Yes sir perfect timing!

[screwwork]

Sweet, that is great news guys!!