I reckon this could be an engineered failure point. It would be the first place to fail, and we see exactly how it did. In a very safe manner.
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Air Arms Why you shouldn’t overpressurize your S4xx/5xx
- Thread starter Sawney Bean
- Start date
Oh boy, the threaded section is exposed to HPA? That'll do it. Wonder the depth of the thread, could easily re-calculate the safe working pressure, but I also think we learned its no more than the manufacturers recommended today.
-Matt
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Interesting idea...
I think I'll stick with 3x or more over pressure insurance, myself...
For what it's worth, we still have 2 AA rifles and they get filled to 200 bar but I would never overfill and still cringe some when filling. One is from 1996, the other from 2000.
Bob
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Bingo. This is actually designed into AA cylinders as an over pressure safety. Have seen this a time or two when owners go too far overboard (be it intentional or accidental) on a fill.
Good post. I own/have owned both S410 and S510 rifles. Never an issue like this and though Motorhead installed HUMA regs in mine, I never have gone above 210 bar, and have this post, will be certain it is filled to no more than 200.
Both of mine are approaching 20 years old with never a problem.
Both of mine are approaching 20 years old with never a problem.
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My own is over 20 years old and has many thousands of pellets through it. You can see by the bluing in the picture that it’s been out in the rain many times over the years.
Up until now I’ve only experienced two problems with it. One had to do with the feed mechanism and I had to order a replacement part, that was about 20 years ago so all I remember is it seemed like a tiny leaf spring. The other was when the baffles in the shroud came loose and I don’t remember what I did to correct it.
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I'm pretty sure it's 200 bar, but prior to regulating it I rarely went above 170 due to the velocity curve. 150 was about optimal for maximum velocity. Once I regulated it I found my most consistent shots were above 160 bar and I was under the impression that the reservoir tube itself was rated to 300 bar, so I felt comfortable overcharging it. It got a whole lot of very consistent shots when charged like that, so I'm a little disappointed, but anytime you walk away uninjured after doing something ignorant and dangerous you should be thankful.
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Not suggesting this as a fix so you can overfill the s5xx/s4xx, but if you were to get a custom fill adapter made that takes the o-ring passed the threads that air tube would be MUCH safer, would certainly give me peace of mind, although as you saw that point of failure wasn't too catastrophic...still well below the margins it should be failing at as it stands.
-Matt
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Yep. The very literal definition of "fail safe."
The new factory regged guns have a vent hole at both ends of the tube.
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I’m not really understanding? Air Arms S-500 series fill to 250 bar 3625 psi working pressure according to every manual I’ve seen and Pyramid airs website. Although I don’t fill mine to that it is the pressure stated unless I’m missing something here?
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Only the newer factory regulated guns have a 250bar fill. Before that, it's always been 200bar.
I sure wasn't bashing AA because I love some of their rifles. One of my all time fav's is the MPR-FT and I like the HFT500, but the thing just doesn't grow on me for some reason. This is also timely, as I just sold my latest MPR and HFT because I'm also not a fan of the triggers, which could be much better, but that's another discussion. I never had any inclination to overfill one, as someone mentioned, the shot curve doesn't indicate the need. Both the MPR and HFT will get a lot of shots on the curve with a ~170 bar fill. Now the fac guns, I understand the want to go higher, but as you can see, this ain't the gun.
I have to admit, as much as I like AA, IF I wanted a gun to shoot in the high speed class, then there are just too many guns that will do it that I like better.
I have to admit, as much as I like AA, IF I wanted a gun to shoot in the high speed class, then there are just too many guns that will do it that I like better.
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So do the mod on both ends...ie: no threading should be exposed to HPA...and in a regulated gun the only end exposed to HPA is the end that failed...
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If you overfilled to 220 bar by accident or because of a faulty gauge @ 72F / room temp and left the gun in your car where it can hit nearly 140F inside, that alone could raise the pressure up to the point of failure OP saw ie: 250 bar..
-Matt
-Matt
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Definitely not a good recommendation, for others to tinker with. As seen and posted about above, it would appear these guns were designed to fail in the manner the OP saw, in a somewhat controlled manner. It someone we’re to redesign the tube to move the oring with the idea of being able to overpressure, then the likely result would be the next weakest part will fail, which may not be as controlled as the OP saw, and could result in injury.
Stubbers, I know you are not suggesting it, but I felt like the result should be pointed out just in case someone thought they could “get away” with it.
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Air Arms - Why you shouldn’t overpressurize your S4xx/5xx
I reckon this could be an engineered failure point. It would be the first place to fail, and we see exactly how it did. In a very safe manner.
www.airgunnation.com No airgun tube should fail in such a scenario. And considering their newer version can handle 250 bar, makes you wonder if they changed the design accordingly...
-Matt
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