What makes mags gas hogs?

[craltal]

Mags also use some of the air to reset the trigger.

[Asym]

Mags also use some of the air to reset the trigger.

Yes, but that air used to reset the trigger still gets routed and used for firing the gun so its not wasted. This is only a problem if you use a RT style valve with a high input pressure. If your used to a reactive trigger when it drops down to around your input pressure or 800-900 PSI your trigger acts different and most people refill. So your loosing some shots because you can't shoot into the tank very deep. So on a 3k tank you only have roughly around 2k worth of usuable air. Many users of electronic framed mags can shoot deeper into the tank since they're not having problems with the trigger reseting with the lower pressure or loss of reactivity. Mine has a custom electronic frame so I can shoot down to 500 PSI, so its got 2500PSI worth of usable air.

athomas, how deep can you shoot into the tank with the 1100 shots?

[b e n]

It uses a smaller chamber at a higher pressure for a faster recharge rate and to move the bolt. Using higher pressure means if there is like 500psi left in the tank it won't fire. Whereas alot of electro pneumatics today can operate just fine at that pressure.

Thats not why because matrixs run at 150 PSI and are air hogs just like mags

[Dark Frost17]

i dont really think they are that bad....but i did notice using the right barrel and paint...like my lapco big shot ss and nightmare.... was alot better then my other barrels ...

[athomas]

athomas, how deep can you shoot into the tank with the 1100 shots?

I think its somewhere around 750 psi, but I'm not sure. I have never actually run out, but I know I have gotten close.

[PnueMagger]

This would also make it cycle faster no?

The main restriction in the mag is the way the on off charges the dump chmber. A smaller dump chamber means higher operating pressure. most other guns use a timed solnoid valve or poppet valve to release the air when the time is right for a certain period time (dwell).

The mag uses it's own bolt to release the air as it travels forward. But remember, while the bolt is forward, the rocker type sear prevents the on/off from opening. This means that the bolt cycle and on off recarge of the dump chamber are codepentant. in a more independant sytem like a cocker, very little pressure is diverted to move the bolt, and the air chamber is always in a state of recharge. Mag AIR regs, while some of the fastest ever made, have a lesser bps capability because they only get a small fraction of the time to refill the dump chamber.

TK being the genious that he is, invented a reg that could "slam fill" the chamber with much higher unregged pressure - the RT valve. The higher pressures coupled with a more effiecent on off meant 26+ bps. This is why we notice RT mags love of high pressure. The higher the pressure - the faster it rips - just ask any Emag owner.

Unfortunately, until AGD gets rid or the bolt spring and On Off Sear design, this is as fast and efficient as mags will ever be. Please prove me wrong though AGD! I know your cooking something up.

[rb211]

My trigger fingers!

[FinchMan]

another reason, is because they use a burst chamber to regulate the velocity of the shot. This makes the pressure curve Large at first then taper off slowly. With poppet-based guns, the pressure curve is much more like a square wave. The square pressure curve is more efficient at accelerating the paintball. This is the same reason all spool-valve guns are gas hogs compared to poppet vavle gun.

... if that makes any sense... I'm going to sleep soon..

[Surestick]

another reason, is because they use a burst chamber to regulate the velocity of the shot. This makes the pressure curve Large at first then taper off slowly. With poppet-based guns, the pressure curve is much more like a square wave. The square pressure curve is more efficient at accelerating the paintball. This is the same reason all spool-valve guns are gas hogs compared to poppet vavle gun.

I understand what you are saying about the shape of the pressure-release/time curve during firing but I don't understand how it applies to efficiency.
I would think that dumping most of the air at once when you have relatively little area between the ball & the bolt (like in a mag or spooler) would be more efficient than providing it more consistently as you say happens in a poppet valved gun.

Seems to me that you'd want to do four things to get an efficient marker design (all other things being equal (barrel length, paint to barrel match, etc):
-minimize blowback.
-minimize the air used to cycle the marker.
-minimize the volume between the valve or dump-chamber & the back of the ball.
-have good control over valve dwell (or in the case of a spool-valved marker make sure the dump chamber isn't charging while its other end is open to the barrel)- no sense in dumping air down that barrel after the ball has left
The first two would explain why most pumps are so efficient as would the 3rd to a certain extent - the simpler the marker design, the smaller this volume would generally be.
If you really wanted to get anal about efficiency you would probably want to "port & polish" all the gas passages in the marker to avoid wasting energy & in a spooler you could tune the dump chamber volume & pressure for max efficiency.
I suspect once you have done all that you would probably find that a well designed spooler & a well designed poppet valved marker operate at close to the same pressure & get about the same efficiency.

[Dayspring]

No they don't.

The incoming air hits the on/off pin & pushes the sear down to lock the bolt in place. No residual air is used to reset the trigger. This isn't a blowback gun.

Mags also use some of the air to reset the trigger.

[RapidTransit]

Well also since is this is coming up check out my design for a searless Mag Valve:

http://www.automags.org/forums/showthread.php?t=197812

[athomas]

I understand what you are saying about the shape of the pressure-release/time curve during firing but I don't understand how it applies to efficiency.
I would think that dumping most of the air at once when you have relatively little area between the ball & the bolt (like in a mag or spooler) would be more efficient than providing it more consistently as you say happens in a poppet valved gun. .....

The square wave type of approach works because all of the pressure is available all the time that the valve is open. In a mag valve, the initial pressure is high, but it trails off and the remaining air is following the ball rather than pushing it. The trailing air is wasted air. By decreasing the volume and increasing the pressure, you empty the chamber faster so the air is available for less time. Less time equates to more efficiency in this type of valve.

[dreadpirate]

Yes, but that air used to reset the trigger still gets routed and used for firing the gun so its not wasted. This is only a problem if you use a RT style valve with a high input pressure. If your used to a reactive trigger when it drops down to around your input pressure or 800-900 PSI your trigger acts different and most people refill. So your loosing some shots because you can't shoot into the tank very deep. So on a 3k tank you only have roughly around 2k worth of usuable air. Many users of electronic framed mags can shoot deeper into the tank since they're not having problems with the trigger reseting with the lower pressure or loss of reactivity. Mine has a custom electronic frame so I can shoot down to 500 PSI, so its got 2500PSI worth of usable air.

athomas, how deep can you shoot into the tank with the 1100 shots?

Well, back when I had a gauge on mine, although the 0-5000 psi gauge on the tank read about 1000psi when it stopped cycling, the 0-1000 psi gauge read about 450 psi. I was using an apex barrel at the time, though so I could not tell if my shots were dropping off, though there was a shift in tonal quality when the air ran low.

[Asym]

Thanks for the numbers Athomas and Dreadpirate. Just asked to show that most mag users can't or don't shoot deep into the tank, so you loose shots.

But if you could shoot all the way down to 500PSI in Athomas case you wuold get another roughly 122 shots for a total of 1222. If Dreadpirate gets roughly the same efficiency as Athomas stopping at 1k would make the available shots 977 with a 88 3k system.

For fun lets compare the mags efficiency numbers with lets say an Ion at its highest given number 1400 shots off a 68 4500 tank. I just want to calculate efficiency for useable air, the Ion will get more shots due to the fact that I'm going to make the asumption that you should be able to shoot down to just above the input pressure of around 150-200PSI.
First we need to calculate the efficiency of a few mags Number of shots/usable PSI = shots per PSI, for mine it would be 1100/2500=.4. For Athomas we need to convert his numbers for a 68ci tank, 1100/88=12.5, 12.5x68=850 for a 68 3k tank, then 850/2250=.3777. The Ion with the asumption that we can shot the tank down to 200PSI should be 1400/4300=.3255.
Shots per PSI of usable air,
My Classic mag=.4
Athomas RT?= .3777
Stock Ion=.3255
Numbers show that the mags are more efficient than a stock Ion, but the Ion like all low pressure guns have more usable air in a tank which makes them seem more efficient.If all these guns used a 68ci 4500 tank,
My classic .4 x 4000 = 1600
Athomas RT? .3777 x 3750 = 1416
Stock Ion .3255 x 4300 = 1399
I can shoot down to 500PSI, Athomas 750PSI, most LP guns can go down to around 200 PSI. That extra 300-800PSI can be quite a few more shoots, it doesn't make them more efficient, just able to make use of more of the available air.

[the mag guy]

I wish I could get my gun half as efficient as all of y'alls. I am running a tuned X-valve w/ lvl X and a tuned ULT. My tank is a 114 Cu In 3000 psi, 800psi fixed output tank. THATS HUGE. I'm not even getting 900 shots with paint! I have no leaks. I dunno wuts goin on.

I do know my gun is a little piggy piggy