WE Gas Blow Back M4A1 Carbine

[bbstriker]

OK. So we have excellent and exhaustive reasons why and how the WE mags explode. It might also help to explore how they could be made not to explode in typical operating climates/temperatures. It seems we genuinely have the knowledge and skills on this forum. If you leave pot metal out in sunshine in ambient temp of 40 celcius then the metal will hover around 55 celcius after about 10 mins exposure. So I'd guess the mags should be built to hold pressure safely up to a max of 60 Celcius and vent gas at 65 celcius. I would then target the mags to withstand an absolute maximum of say 70 celcius.

 

And by the way, one has exploded inside a Post Office out of sunshine. It's may also be pertinent that there are (currently) no reports of WA mags blowing up. Could this be why WA mags are so much more expensive than WE mags?- I don't know.

 

From the threads here, I guess WE will take action when someone gets hurt and when that happens the problem turns into an official health and safety issue. A dangerous strategy because if it happens, in a Health and Safety paranoid society such a the UK, just about ever Airsoft Site owner will ban WE M4 GBB weapons at their sites. I for one would sell my WE and so will many others if that happens.

 

We cannot rely on work-arounds- i.e. keep them in the shade. If I'm lying in an OP at 30 celcius in overhead sunshine, my mag will quickly heat up to around 45 and therefore I'd be at serious risk of injury- NOT ACCEPTABLE! My mag explode at well below that (approximately around 35 celcius) temperature.

Edited May 28, 2009 by bbstriker

[Chris North]

WA mags cost so much because of where they're made and who they're made by. They are only slightly more complex than WE mags. They also probably don't explode because they leak with the slightest bit of mistreatment on propane (for example, filling them with propane).

 

It's definitely an issue. Keeping your filled mags out of high-heat environments is the obvious and common sense solution, but the question of what exactly constitutes "high-heat" could be raised considering that like all gas guns the WE M4 is designed to work in warm environments and cold isn't exactly it's preferred operating environment. A safety valve however would in my opinion mostly just jack up the price of a mag and allow another point of failure for gas to leak out in normal conditions.

 

However this all might just be my misguided opinion spat-out in a sleep-deprived state since I still haven't seen a photo of exactly where one of the mags has failed.

 

 

 

[Marky [UE]]

Valid heat concerns aside I need to know what we consider to be an acceptable seal. WETTI stated that trying to completely seal the mags is not a good idea as the design allows for high pressure bleeding. I recently had to dismantle and fix both my mags due to poor factory assembly; I can explain how if anyone is interested. Having fixed the first issue I submerged both filled mags in water to test and I have very slight leaks out of the top and bottom points of the long back seal. I have assumed this should not be the case, but taking the official statement I don't want to fully seal the mag. Suggestions/experience would be appreciated.

Edited May 28, 2009 by Marky [UE]

[newcomer]

our M4 mag internals are designed with escape channels for excessive pressure as a safety measure.

 

WETTI

 

With all due respect, where are the escape channels located in the magazine? If there exists a safety measure for excessive pressure (how much do you define excessive?) build up then why do magazines still explode from over excessive pressure? Clearly, the logical conclusion is that there is in fact, either no safety measure, or the so called escape channels aren't doing what they're designed to.

 

Anyways, it doesn't matter because it's only a matter of time before someone gets hurt (this includes damage to property) from exploding magazines. The manufacturer should realize that she is directly liable should the victim file a lawsuit, frivolous or otherwise. Add this to the fact that the manufacturer had prior knowledge that the magazines, a Catergory B Simple Pressure Vessel under the 1991 Safety Regulations (SI 1991/2749), did in fact fail due to the absence or failure of a safety device, and had not taken appropriate measures makes it even more detrimental for the defence. To be fair, the regulation does provide a defence of due negligence.

 

Well it pays to be safe than sorry.

 

You know how a lawsuit against your company can affect your image and the repercussions that follow. Listen to us on this one and make us safer magazines, please?

[lukvdh]

...

It's definitely an issue. Keeping your filled mags out of high-heat environments is the obvious and common sense solution, but ...

 

 

To me this "solution" sounds like "keep your car off the road to avoid accidents".

"Do not drive your motorbike so you don't get injured".

[ViciousV10s]

I believe that only holds true if the temperature remains constant. In this case temperature does not remain constant it increases. So even though a pistol mag has a smaller volume it's still a constant, since it's a vessel and same with the GBBr mags. Therefore, as temperature increases so does the pressure.

 

Again, for your uneducated people; pV=nRT

 

Go take a chemistry class or two. "R" is the only constant in that equation.

 

Pressure and Volume are both directly proportional to Temperature. Temperature can NOT remain constant if either volume or pressure values change. And vice versa for them all.

 

The size of the enclosure is NOT the "volume" of the gas. Volume is the amount of space the gas is actually occupying within the enclosure.

 

Every time you fill a mag with gas the actual volume within the mag changes, do to all the VARIABLES in the above equation, both on the mag and on the bottle/tank of gas being used to fill the mag.

 

Seriously, go learn something before trying to have an educated discussion.

 

I sill do not believe there is anything to be worried about with these WE M4 mags, they've been out for quite some time now and other than these stupid stories of mags being exposed to excessive sunlight and heat these mags are not just randomly exploding.

 

Just think about the GreenGas you can buy online these days. How long did it take for the older gas cans to get banned from online shipment ordering because of safety reasons?? and how many of them exploded and injured people?

 

You guys are worrying about nothing. Use and store your mags properly. The end.

Edited May 28, 2009 by ViciousV10s

[slu]

Again, for your uneducated people; pV=nRT

 

Go take a chemistry class or two. "R" is the only constant in that equation.

 

Pressure and Volume are both directly proportional to Temperature. Temperature can NOT remain constant if either volume or pressure values change. And vice versa for them all.

 

I don't want to start argument, but it's not right to dismiss what freq88 said, since it is valid in some way of thinking:

 

Suppose you start off at state 1, at P1, T1, V1. You goto some V2 = 3 V1 by some process. Only by assuming isothermal process (i.e., T1 = T2 = T), can you get P2(3V1) = NkT, P2 = (1/3)P1. You say that if you increase volume by factor of 3, you will decrease pressure by factor 1/3. This is true, only if the process by which you increased the volume is isothermal. Otherwise, your one equation of state (the ideal gas law) is not sufficient to solve for the final pressure or temperature.

 

However, since I think you are speaking of "two similarly prepared systems," both at the same temperature but one at three times the volume of the other, then the comparison is valid.

 

The size of the enclosure is NOT the "volume" of the gas. Volume is the amount of space the gas is actually occupying within the enclosure.

 

Every time you fill a mag with gas the actual volume within the mag changes, do to all the VARIABLES in the above equation, both on the mag and on the bottle/tank of gas being used to fill the mag.

 

I'm not chemist, but that's a hard thing to assume. Assuming it is still a gas, for it to not take the entire volume of the container requires one of two things: 1.) Intermolecular forces (i.e., van der Waals or whatever, arguably possibly), or 2.) a potential inside the container (which is arguably true, since there is gravity). The thing is, under the ideal gas assumption (the assumption you make by using PV=NkT), those things are both assumed zero. So, under those conditions, there is no reason why an ideal gas wouldn't take up the entire volume: there are no attractive forces stopping it: mean free path is infinite, until you collide with the wall, so the pressure is uniform everywhere along the container walls.

 

This is of course, ignoring phase transitions (so liquid to gas in this situation). Obviously, liquid will not take the volume of its container, but then again that situation cannot be described by ideal gas law.

 

That's as far as I know. But the fact that remains is that if temperature goes up, pressure goes up (by some relation) in most hydrostatic systems.

Edited May 28, 2009 by slu

[redline]

Again, for your uneducated people; pV=nRT

 

Go take a chemistry class or two. "R" is the only constant in that equation.

 

Pressure and Volume are both directly proportional to Temperature. Temperature can NOT remain constant if either volume or pressure values change. And vice versa for them all.

 

The size of the enclosure is NOT the "volume" of the gas. Volume is the amount of space the gas is actually occupying within the enclosure.

 

Every time you fill a mag with gas the actual volume within the mag changes, do to all the VARIABLES in the above equation, both on the mag and on the bottle/tank of gas being used to fill the mag.

 

Seriously, go learn something before trying to have an educated discussion.

 

I sill do not believe there is anything to be worried about with these WE M4 mags, they've been out for quite some time now and other than these stupid stories of mags being exposed to excessive sunlight and heat these mags are not just randomly exploding.

 

Just think about the GreenGas you can buy online these days. How long did it take for the older gas cans to get banned from online shipment ordering because of safety reasons?? and how many of them exploded and injured people?

 

You guys are worrying about nothing. Use and store your mags properly. The end.

Chill out, dude. Your attitude just makes you look stupid. Freq88 WAS TRYING to have an educated discussion. Too bad your immature response just negated everything you have to say.

 

I don't know whether poor craftsmanship or quality control (ie leaky mags) count as "escape channels". I'm not saying the WA are any better...in fact, they suck at keeping a seal. But one thing they got right was the lack of exploding mags. Why should WE be any different? I mean, what would you rather have? Exploding mags or non-exploding mags? I'm guessing this is one of the reasons that the WAs are sooo much heavier.

[newcomer]

Chill out, dude. Your attitude just makes you look stupid.

 

I was thinking the same

 

Fact is vicious we've heard too many stories of exploding mags. I for one would rather believe that than lie to myself that those are nothing more than bs. Come on, what would one gain from lying about exploding mags?

 

The known recorded temperature for WE mags to explode was at 40C, can Net Ronin confirm this? It wasn't just his, his friend's as well. I believe another member here had his explode at 35C? What's the max operating temperature WE's mags were designed to work at again? No specifications on this...

 

Assuming the mags suffer a catastrophic failure at 40C (propane vapor pressure 170ish PSIG), this would put WE mag's safety factor at only 1.3 assuming the max operating temperature is at room 27C (propane vapor pressure 130 PSIG, safety factor = 170/130). This is a already a conservative calculation and the safety factor is only dangerously diminished for every degree warmer. I'm sure ambient temperature is more than 27C during summer...

Edited May 28, 2009 by newcomer

[bbstriker]

.

 

I sill do not believe there is anything to be worried about with these WE M4 mags, they've been out for quite some time now and other than these stupid stories of mags being exposed to excessive sunlight and heat these mags are not just randomly exploding.

 

Just think about the GreenGas you can buy online these days. How long did it take for the older gas cans to get banned from online shipment ordering because of safety reasons?? and how many of them exploded and injured people?

 

You guys are worrying about nothing. Use and store your mags properly. The end.

 

I'll post pictures of the mag that exploded when it attained just a max around 35 celcius- and I'm being pessamistic because ambient temp was no more than 20 celcius. I'll also post pics of my ceiling with bits missing. An exploding propane mag is a frag grenade. It could have torn into a person- more specifically someone's eyes. The various bits of SHARP pot metal were sprayed all over the room. Do you really think it just goes 'pop' ?

 

What sort of pressure will rip apart the outer mag casing and them project shrapnel at sufficient velocity to take chucks out of my ceiling??? You've got to be kidding or very wishful if you think one of these exploding mags will not injure someone sometime soon.

Edited May 28, 2009 by bbstriker

[newcomer]

Dude the man just got his rifle 2 weeks ago, cut him some slack and in time he'll find the good the bad and the ugly of this system. Having said that, I still love shooting mine but I feel this is ONE OF THE major issues that need addressing.

[bbstriker]

Dude the man just got his rifle 2 weeks ago, cut him some slack and in time he'll find the good the bad and the ugly of this system. Having said that, I still love shooting mine but I feel this is ONE OF THE major issues that need addressing.

 

Yep, the WE M4 is the best M4 GBB - mine rocks!

[ViciousV10s]

OK OK I apologize for flying off the handle gents.

 

BBstriker, I'm glad you weren't killed by that frag grenade of a mag.

 

I'll leave the rest of this discussion up to those of you who are actually concerned with overheated exploding mags.

 

As for me, I'll just continue to keep my mags out of direct sunlight exposure until you all figure out how to let them overheat without exploding.

 

 

 

Cheers Mates!

[ViciousV10s]

I was thinking the same

 

Fact is vicious we've heard too many stories of exploding mags. I for one would rather believe that than lie to myself that those are nothing more than bs. Come on, what would one gain from lying about exploding mags?

 

The known recorded temperature for WE mags to explode was at 40C, can Net Ronin confirm this? It wasn't just his, his friend's as well. I believe another member here had his explode at 35C? What's the max operating temperature WE's mags were designed to work at again? No specifications on this...

 

Assuming the mags suffer a catastrophic failure at 40C (propane vapor pressure 170ish PSIG), this would put WE mag's safety factor at only 1.3 assuming the max operating temperature is at room 27C (propane vapor pressure 130 PSIG, safety factor = 170/130). This is a already a conservative calculation and the safety factor is only dangerously diminished for every degree warmer. I'm sure ambient temperature is more than 27C during summer...

 

 

The only and last thing I want to say about the claimed temps of the mags is that the people don't actually KNOW what temperature the MAG was at when it exploded. Just because it was in an environment where the ambient temp was "40C" you have no way of knowing the actual temp the MAG reached sitting in direct sunlight.

 

So who wants to go take one of those IR temp gauges, put their mag in the sunlight, and wait for it to explode so we know what the real point of failure is?

[LordElpus]

The only and last thing I want to say about the claimed temps of the mags is that the people don't actually KNOW what temperature the MAG was at when it exploded. Just because it was in an environment where the ambient temp was "40C" you have no way of knowing the actual temp the MAG reached sitting in direct sunlight.

 

So who wants to go take one of those IR temp gauges, put their mag in the sunlight, and wait for it to explode so we know what the real point of failure is?

 

with a WA mag next to it for control purposes.

[newcomer]

I think you're missing the point vicious. The fact that they could explode when exposed to sunlight on a hot summer day as opposed to aerosol cans and propane tanks calls for a trip to the drawing board. Furthurmore, I remain doubtful on the "escape channels" as claimed by WETTI.

 

It is silly for you to suggest that we as customers pay the manufacturer for the magazines and then conduct a destructive test on behalf of them. I wouldn't mind spending time if it was a non-destructive test, or the manufacturer provides me the magazines for the test if they are confident on the safety of their magazines. The latter would might as well be done by the manufacturer themselves.

 

You're right in deciding to say the last thing on mag temp, as I think there might not be more educated discussion coming from you.

[yubbermax]

Not exponentially actually...volume is inversely proportianal to pressure; pV=nRT

 

If volume expands 3 fold, then pressure will be 1/3 of the original value.

 

I was thinking of the wrong equation... it's only my first year of chem...

 

 

 

[Net Ronin]

The only and last thing I want to say about the claimed temps of the mags is that the people don't actually KNOW what temperature the MAG was at when it exploded. Just because it was in an environment where the ambient temp was "40C" you have no way of knowing the actual temp the MAG reached sitting in direct sunlight.

 

So who wants to go take one of those IR temp gauges, put their mag in the sunlight, and wait for it to explode so we know what the real point of failure is?

FYI, mine exploded during the night in a bed room. There was no Sun's light at all that moment. My friend's mag exploded because he left his exposed to direct Sun 's light since then all members in my team have kept mag from direct Sun's light. I have never used CO2 with my BB guns.

Edited May 29, 2009 by Net Ronin

[renegadecow]

with a WA mag next to it for control purposes.

A magazine of a different design and manufacturer hardly constitutes as control. Control should be a WE magazine under the shade exposed only to ambient temperature.

 

I'll also put into the mix that WE mags CAN actually be overfilled. Open up any Japanese gbb magazine and you'd find the fill valve to have some kind of tubular extension of sorts (roughly to half the length of the reservoir). This limits the amount of liquid pumped into the mag thereby limiting the possibility of it being over filled and reach destructive pressures. This tube is absent on the WE mag so as long as you jam that can of gas in the mag, its going to pump in fuel until its full to the brim. I believe installing this simple device should work in keeping mags from blowing up because other than exploding from excessive heat, all cases are similar in that they were just previously filled and possibly overfilled.

[lukvdh]

....

So who wants to go take one of those IR temp gauges, put their mag in the sunlight, and wait for it to explode so we know what the real point of failure is?

 

WE should be doing this.

And they should have done this "long time ago".

 

[freq88]

I'm sorry I'm relying on my pubic edumication and daylighting career for information here. And I will aimlessly attempt to back it up with a lot more uneducated reasoning. That I did not want to present needlessly in the first place. Figuring that a highly educated person as yourself would first consider and weigh an oppossing argument before dismissing it.

 

Every time you fill a mag with gas the actual volume within the mag changes

Wrong, you're actual volume remains the same since it's the total volume of the mag. In order to use your law we have to be dealing with a completely vapor state, which we are not. In our case we're dealing with both the liquid and gas state of propane. The specific volume of gas changes as the ratio of liquid vs. vapor propane changes due to ambient temperature and discharge during use. However, the liquid does not affect the pressure since it has such a low boiling point at standard atmospheric pressure. Therefore, the pressure of propane is primarily determined by ambient temperature.

 

Some more uneducated reasoning...

At standard atmospheric pressure (0 PSIg) Propane boils at -44*F. Let's say we're able to fill our magazine at -44*F so it pure 100% propane. The volume of the mag hasn't changed has it? No it still holds the same amount of propane. Now we bring it up room temperature at 72*F. At which time the liquid propane boils off into a vapor it will begin to expand and compress within the mag until the pressure is capable of raising the boiling point above 72*F (Which will about 115 PSIg). The volume of propane hasn't changed has it? No, because it's still 100% propane. It is just that ratio of propane in liquid and vapor state has changed. Therefore, pressure is directly proportional to temperature.

 

I say it's the material and design of the mag. The plate on top of the mag under the "face seal" I believe is the pressure release valve. But even under room temperature this plate can still leak, which makes it worthless since we're wasting gas for no reason. Casting is a poor method for creating any form container that will be subjected to pressure especially, when it's material pot metal and as thin as the walls are. Look at refrigeration pipes they're only 1/8" thick walls yet some systems have pressures in the 300-400PSIg range and are constantly subjected to direct sunlight and high ambient temperatures.

Edited May 29, 2009 by freq88

[Andrew March]

Has anyone else had any problems getting the front sight off their M4, it almost feels as if the sight block is part of the barrel!

[freq88]

Your front sight is held on by a set screw underneath the sling mount in addition to the 2 pins.

[Andrew March]

Outstanding, thanks man

[Pantelis]

Does anybody know how the brass cylinder that the Nozzle goes in, can be taken out? I want to install the CO2 nozzle and i am afraid that i will damage my gun...