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Posted: 10/13/2009 5:23:02 AM EDT
| I hear talk about difference in heat build-up of a rifle length gas system vs the m4 gas system. What is the actual difference in gas temps blowing into the receiver between the 2 different lengths? Just curious, I went with a midlength set-up and that was one of the selling points for me along with the fact that my bayo would work on it. |
| I don't know the actually temp but just looking at it with the differences in the lengths, one could easily infer how the rifle would not get as hot as quickly because it has more area to dissipate heat. Allso the gas has a longer tuber to go down which gives it longer to cool. |
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That's what common sense tells you but I'm curious if anyone has actually studied it.
Maybe someone can do a test on their rifles. 20 rounds through a rifle length with a temp check then 20 rounds through a carbine with a temp check. I want some hard data to read. |
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you want to measure the temperature of the gas coming out of the gas tube on a carbine, middy and a rifle length Gas system? Probably a tough set up there.
I don't think there would be an measurable difference in the gas temp. Maybe the first round fired in the winter would measure a difference as the gas tube is longer and can cool the gasses a bit? BUT after the gas tube is hot I don't see any reason for a gas temperature difference. Now the rifle will certainly cool quicker but the gas temperature itself I'm skeptical. |
| But the temp will not be from the gas. The heat will be from the metal conducting the heat from the chamber gas tube not from just the gas itself. I have no way of measuring the heat of the gas. With a laser thermometer all you will be doing is gathering the heat that the metal conducted. To get the heat of the gas you would have to have something to gather the temp when it enters the gas port and then something that measures it when it drives the carrier key back. That is the only way to tell. |
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I'm just as curious about the end result which will help answer the question. The end result is how fast does the heat build up in the receiver on a rifle vs carbine length gas system? If it builds up faster in the in the carbine then that should answer the question whether there is a measurable drop in temp in a rifle length system vs the carbine.
I'm thinking about these questions after reading about piston systems being much cooler after firing where there is no gas blowing back into the receiver and reading the recent article about so called failures in the recent Afghan battle. Maybe someone could throw a piston set-up into the same test. |
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Maybe you should go this way:
Same amount of heat transferred to same mass of same material will give same temperature. So if more heat is transferred then incerease of temperature should be noticeable. Get rifle and carbine, try to shoot same amount of ammo (for eg 30rd of rapid fire, 60 rd of rapid fire and 90rd of rapid fire) in same time period then measure bolt temperature. Try to do all things with same pace. This excercise (if done properly from methodology view) should generally answer your question if more heat is comming in carbine or not. If you want to calculate relative heat increase (for eg. 30% more heat in carbine) then some more complicated calculations are to be made and degrees Kelvin should be used. |
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Quoted:
Maybe you should go this way: Same amount of heat transferred to same mass of same material will give same temperature. So if more heat is transferred then incerease of temperature should be noticeable. Get rifle and carbine, try to shoot same amount of ammo (for eg 30rd of rapid fire, 60 rd of rapid fire and 90rd of rapid fire) in same time period then measure bolt temperature. Try to do all things with same pace. This excercise (if done properly from methodology view) should generally answer your question if more heat is comming in carbine or not. If you want to calculate relative heat increase (for eg. 30% more heat in carbine) then some more complicated calculations are to be made and degrees Kelvin should be used. I thought that was what I said? |
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