Why is nitro quieter?

[battlegroup]

Originally posted by Rampage
That ping you hear is likely from the sound echoing through the liquid co2 in the tank.

-Joe

I know, I just didn't want to make my post any longer explaining it. The carbon fiber wrapping on the tank has some noise deadening properties for the tank as well.

[Magluvr]

Battlegroup-
The Nitro tank was filled off of a scuba. I say n2 because that is essentially what it is since air is primarily n2. I didn't mean that I had 100% n2 in the tank.

Seriously do you think that I am that stupid. I chronoed both the markers and they got the exact same velocity. Then just for the heck of it I adjusted my stabilizer so that it was the same velocity as his n2 tank. I did it so no one could argue "Well the pressure going into the gun is different so that is the reason." I was NOT using the same input pressure to determine that the velocity was!

No there is no ping with either the co2 or the n2. So that is NOT a factor in this topic.

No the velocity as stated earlier in this reply is at the same with his n2 and my co2. And both the tanks are made out of steel. And neither gun pings.

[battlegroup]

Originally posted by Magluvr
Battlegroup-
The Nitro tank was filled off of a scuba. I say n2 because that is essentially what it is since air is primarily n2. I didn't mean that I had 100% n2 in the tank.

Seriously do you think that I am that stupid. I chronoed both the markers and they got the exact same velocity. Then just for the heck of it I adjusted my stabilizer so that it was the same velocity as his n2 tank. I did it so no one could argue "Well the pressure going into the gun is different so that is the reason." I was NOT using the same input pressure to determine that the velocity was!

No there is no ping with either the co2 or the n2. So that is NOT a factor in this topic.

No the velocity as stated earlier in this reply is at the same with his n2 and my co2. And both the tanks are made out of steel. And neither gun pings.

Now you didn't give us this info in your first post now did you? Don't get on me because I asked if you had done some things or made suggestions you didn't say you chronoed you said to redkey you were running the same reg...not the same thing!!!

Also both tanks may be steel but they are not the same tank and different sizes and shapes affect sound transfer even if they are the same material. Yours may not ping but it may add some noise.

Are you using the exact same barrel on both guns? are they the exact same set up? Same paint? A smaller bore paint may change the amount of noise heard out the end of the barrel becasue more air escapes around the ball. Are both barrels clean? A dirty barrel will be louder because it has more friction and requires more air to push a ball to the same velocity. Do you both run the same bolt? There are a thousand different reasons one gun may be quieter than another.
I chronoed both the markers and they got the exact same velocity.
Ok so they are at the same velocity

Then just for the heck of it I adjusted my stabilizer so that it was the same velocity as his n2 tank.
Do you mean pressure instead of velocity?

I did it so no one could argue "Well the pressure going into the gun is different so that is the reason."

Pressure going into the gun wouldn't matter because mags have the AIR reg on the gun.

If you take one gun and put co2 on it and it fires 300fps and then take the same gun to keep everything the same and put compressed air on it and don't change the velocity setting on the gun and it fires at 300fps then both gasses expand at essentially the same rate because if one expands faster then the velocity would increase.

The sound however is not solely linked to the expansion rate of the gas. the physical set up of the marker comes into play. the aspect at which you are relative to the barrel. the more things you can make the same the better your test is.

I could keep going but this is long enough as it is.

Bottom line I wasn't insulting your intelligence in my first post, you didn't provide the info!

[cky shane]

No, sorry, you're wrong. On SO many levels. Where to begin:

Also both tanks may be steel but they are not the same tank and different sizes and shapes affect sound transfer even if they are the same material. Yours may not ping but it may add some noise.

Nothing to do with the report of the gun. The gun is constant air... the output pressure remains constant whether or not the valve is open. Tanks pinging (which he says they aren't) would be the only sound quality that would depend on the tank. You aren't honestly suggesting sound waves are reverberating through the tank, are you?

A smaller bore paint may change the amount of noise heard out the end of the barrel becasue more air escapes around the ball.

That's the only correct statement you've made and it disproved your entire point. Congratulations.

Air is bled off through the barrel's porting. The amount of air is dependent on the expansion rate of the gas (how fast it can escape through the porting and, therefore, how much escapes per shot.) If the gasses have different expansion rates (and I'm betting they do), that will produce the different in volume. Expansion rate isn't a null factor--it's the biggest known variable.

Pressure going into the gun wouldn't matter because mags have the AIR reg on the gun.

The AIR reg is adjustable (what's how we tune velocity.) Your state means little more than his.

If you take one gun and put co2 on it and it fires 300fps and then take the same gun to keep everything the same and put compressed air on it and don't change the velocity setting on the gun and it fires at 300fps then both gasses expand at essentially the same rate because if one expands faster then the velocity would increase.

Not necessarily. It depends on the length and porting of the barrel, too. Guns are chronographed at the muzzle, meaning there is still a length of barrel in which the ball begins slowing down. If you measured at the first porting, I would agree that they would be the same. It's possible that the porting on his (or, more likely, most) barrels end up producing the same negative velocity change from the first porting to the muzzle. This is due most likely to the inaccuracy of chronographs (1 significant figure ) and similar expansion rates between the two gasses. However, I'm willing to bet the proportionality between the volume of the report and pressure is a P = Db^2 relationship and the proportionality between the velocity of the projectile and pressure is a P = V.

The sound however is not solely linked to the expansion rate of the gas. the physical set up of the marker comes into play. the aspect at which you are relative to the barrel. the more things you can make the same the better your test is.

Solely, definately not. Chiefly, probably. Air source is the most obvious, largest factor that was manipulated and based on my knowledge of Chem and Physics, I'm betting that it's the source.

By the way, compressed air is made up of alot of light gasses (Nitrogen, Helium, and Oxygen are all comparatively light gasses.) CO2 is considerably heavier, which would explain the difference in expansion rate on the molecular level, in addition to the operational level. it's safe to say the expansion rate of Compressed Air is greater than CO2--the question is to what effect it has on the gun. I've put methodical evidence forth to support my hypothesis and while I won't claim to use his experience as an experiment, I think my hypothesis has alot more basis and support than yours.

[battlegroup]

Not necessarily. It depends on the length and porting of the barrel, too. Guns are chronographed at the muzzle, meaning there is still a length of barrel in which the ball begins slowing down. If you measured at the first porting, I would agree that they would be the same. It's possible that the porting on his (or, more likely, most) barrels end up producing the same negative velocity change from the first porting to the muzzle. This is due most likely to the inaccuracy of chronographs (1 significant figure ) and similar expansion rates between the two gasses. However, I'm willing to bet the proportionality between the volume of the report and pressure is a P = Db^2 relationship and the proportionality between the velocity of the projectile and pressure is a P = V.

If the gases expand at the same rate, they will expand out the porting at the same rate!

Not necessarily. It depends on the length and porting of the barrel, too. Guns are chronographed at the muzzle, meaning there is still a length of barrel in which the ball begins slowing down.

UMM NO. If you have a long enough barrel the ball will start to slow down but with the right length barrel the ball will accelerate through the entire length. If the ball slows down in the barrel your efficiency will suffer becasue you will have to accelerate the ball to a higher velocity that what you want to chrono at to compensate for the slowing down. If you have too much porting it will slow down and you will use more gas. but not all porting will cause the ball to slow down in the barrel.



Sound reverberation through the tank will change the total sound put out by the gun. If you are in front of the gun you will hear mostly report of the barrel if you are next to the gun firing it, the reverberation of the sound through the gun will have a more pronounced effect, maybe not more than the report but it is there.

Case in point I thought my mag was very loud on CO2 when I fired it until I had several people claim I was hard to find becasue my gun was so quiet. When I let someone else fire it at me it too found it was very quiet. However when I was right next to the gun it sounded very loud. when I changed to HPA, the sound I heard from firing it was decreased but it was still just as quiet when fired at me. Of course different set ups will react differently but in my physical test on this matter the greatest sound reduction came from being in the firing position but several people agreed that it was the same when I shot it at them.

Part of my argument was to point out that magluvr did not give us enough info in his original post about how he tested his marker.

Also the pressure going into the gun wouldn't matter unless it was less than the AIR reg needed to push the ball up to velocity. Th pressure input to the gun has no effect on sound just recharge rate and shootdown.

How did the smaller paint theory disprove my point, if the guy was using larger paint with CO2 and then when he got his HPA tried it with smaller paint the sound would be reduced by the paint not the HPA. READ THE POST

I am trying to point out that there are several factors that are associated with the perceived sound a marker makes.
Also it depends on where you are when you say it is quieter. You can give me all the theory you want. I actually tested it and found that at the same velocity with the same paint, barrel, and gun set up besides the type of tank and the gas, that the noise from the shooting position was reduced a lot more noticably than the sound of the gun being fired at me.
This test on MY marker led me to believe that the change in tank had a noise deadening effect on the gun, more than the change of gas did

[cky shane]

I'm saying that there is nothing to support your conclusion. Unfortunately, what you percieve while playing doesn't really qualify. Until someone conducts an experiment one way or the other, there's no reason your suggestions should even be considered.

[battlegroup]

What I said in my first post on this topic

The only way to test it is with a decibel meter at the end of the barrel with each gas pushing a ball at the same fps.

Everything else I was suggesting was probable causes of noise change! AND there is no reason my suggestions should not be considered until someone does do a more scientific experiment.