CO2 and barrel breaks in mags

[ghost flanker]

Has anybody else experienced a significant increase in barrel breaks when running CO2 into their classic mags vs compressed air? No, not chops. I mean barrel breaks. Because I seem to have had this problem with my pump mag when shooting fairly brittle paint at 280 fps. But screw in a compressed air tank and it shoots the same paint just fine. I run my pump mag as so.


MOTM config

Current config

Could liquid CO2 still be getting into the valve? The tank is vertical, my rate of fire is slow, and am not shooting hot at all -- nothing above 300 fps -- so what gives?

By the way, as a side note, when the 13ci Ninja tank is filled to exactly 3000psi (according to the gauge), it yields about 134 good shots (a good shot = anything over 249 fps) when dialed in at 280 fps and using a minimag barrel with .685 diameter paint. With all else being equal, the 3.5 oz got 93 good shots. Just thought I'd share my results.

[Nobody]

No, it shouldn't but i think it has more to do with the coldness or temp change of ambiant air then a blast of the co2 hitting the ball on that fragile paint than anything else. If it is shooting fine on HPA, then co2, then the only variable is the co2. As it is not the barrel, valve or loader. Also, with the co2 in the verticle position, unless you tip the tank over to put the liquid into the valve, its not liquid co2.

[Nobody]

Also, co2 has more potential energy than HPA, but it matters on how much liquid co2 can expand(3.5oz is not a lot of room) and on how much liquid can turn gaseous. You could try running the co2 tank with a neoprene cover to help warm it up, and even set it in the sun before you use it to help flash the liquid over.

If you feel that it could be liquid getting into the valve (highly doubt it as the urethane and teflon orings qould all be trashed by touching liquid and it would be leaking everywhere), putting an anti-siphon tube in the tank will help. I have seen either a J or a U shaped tube coing out of the valve, basically a snorkel, drawing only gas co2 and even a weighted flexible tube that no matter how you hold the tank, the weight keeps the air hole out of the liquid. That is old 90s tech and it works.

[Spider-TW]

Try a longer barrel on CO2. That short barrel (relatively large bore at that) is shorter than CO2 expands efficiently. The CO2 is jetting out and puncturing the ball because you have to put a lot out initially to get the velocity up. It is worse with a devolumized valve, due to the higher pressures. My son had the same problem that a longer barrel would fix, but he insisted that he liked the short barrel anyway.

[athomas]

If you are using a vertical tank, don't install an anti-siphon. The vertical position is ideal for keeping CO2 out of the ASA. Anti-siphon tubes are generally used on horizontal or bottles that are tipped back on an angle.

The gas contained in the dump chamber will have more mass when using CO2 than when using compressed air. This won't manifest itself in much of a difference in the actual velocity, but the farther you get from ideal operating conditions, the more effect it has. A few fps difference in velocity can be quite a bit more force on the ball in the chamber. That could be the difference you are experiencing and it might just be enough to get past the breaking point of the balls due to the faster acceleration of the bolt. The mass density of CO2 is 1.5 times higher than compressed air at operating temperature. Since the energy transfer is directly related to the mass of the colliding objects, CO2 has a greater ability than air to transfer its energy to the ball at any given pressure. It won't be 1.5 times greater, because its mass also works against it causing the gas to be less responsive due to acceleration of the heavier gas through the air passages (the bolt). In the end, it does provide some increase in energy transfer. As mentioned above, the longer barrel will help because of the slower acceleration rate of the CO2 gas. This will allow you to turn down your velocity (pressure) setting and achieve the same velocity results as with the shorter barrel.

[ghost flanker]

Spider-TW,
I'm the same way as your son; I'd rather keep the short barrel, especially for my gun. It's gotta stay a pistol. Though the Ninja 13 ci tank is significantly taller than the 3.5 oz tank, it's practically the same weight, and it holds almost 50% more shots, anyway.

athomas,
That helps clarify what's going on. Before, part of me was wondering whether I could get a Palmers Stabalizer or something and mount it horizontally along the right side of the body to eliminate the chances of any liquid CO2 ever getting in the valve. Clearly, doing this would not help my barrel break issue. Compressed air, it is.