1) so the bigger the chamber the more power u will get?
2)if i have a 2 1/2 foot barrel, 1/2 width...how big would my chamber have to be for the best preformance? and how far would it shoot horizontally on a football feld?
my bad for mnumber 2 make it an 3ft long barrel
2 questions...once again
1) Basically, but obviously you should keep the ratios in mind because you could have a 4"x20' chamber and a 1"x1' barrel and since the ratio is so far off your ammo wouldnt go anywhere. Know that I think about the flame would go farther then the projectile.
2) Go to burntlatke.com and use his caculator. I could give you a guestamation of how big it should but I would rather help you turn into self suffeciant (that word is freakin hard to spell) spudgunner.
2) Go to burntlatke.com and use his caculator. I could give you a guestamation of how big it should but I would rather help you turn into self suffeciant (that word is freakin hard to spell) spudgunner.
Nice double post 
Please use the edit button. Its called a C:B ratio (chamber: barrel) So I dont know where you got the third number from. Your c:b ratio should be about 1:1 or 1.5:1. You can toy around with ratios a little bit like thought 6:1 or 1:6 those numbers wouldnt be good.
Please use the edit button. Its called a C:B ratio (chamber: barrel) So I dont know where you got the third number from. Your c:b ratio should be about 1:1 or 1.5:1. You can toy around with ratios a little bit like thought 6:1 or 1:6 those numbers wouldnt be good.-
boilingleadbath
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1) Yeah, big chambers are good. The only exception is when the time the propellent has takes so long that the pressure never gets very high before the ammo has left the barrel. (the empty salt mine scenario)
However, because you are limmeted to a total launcher length, and preformance return on volume invested is deminishing (1:1 -> 2:1 gives a biger improvment than 2:1 -> 3:1), there is an optimum trade-off between long barrel and long chamber. This is an elusive number, dependent on many things; chamber <i>diametr</i>:barrel <i>diameter</i> ratio, fuel, how you figure it out... and is still a tenative branch of study.
... nevermind, I see you are limmeted by barrel length. Just make a big chamber.
2) as big as possible - make the best use of that punny 3' barrel!
However, because you are limmeted to a total launcher length, and preformance return on volume invested is deminishing (1:1 -> 2:1 gives a biger improvment than 2:1 -> 3:1), there is an optimum trade-off between long barrel and long chamber. This is an elusive number, dependent on many things; chamber <i>diametr</i>:barrel <i>diameter</i> ratio, fuel, how you figure it out... and is still a tenative branch of study.
... nevermind, I see you are limmeted by barrel length. Just make a big chamber.
2) as big as possible - make the best use of that punny 3' barrel!
awesome thx man so 1:1 is good right? so how good would it be?
so witha a 3ft barrel/9.5'' length, 1 1/2'' width chamber and a ratio of 1:1 its gonna be the best it can be with that chamber size?
EDIT: im a retard its 1:1 not 1.1:1...ok i got it now thx
so witha a 3ft barrel/9.5'' length, 1 1/2'' width chamber and a ratio of 1:1 its gonna be the best it can be with that chamber size?
EDIT: im a retard its 1:1 not 1.1:1...ok i got it now thx
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boilingleadbath
- Staff Sergeant 2
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Hu?
Your 3' long, .5" diameter barrel with your 9.5" long, 1.5" diameter chamber will give you a ratio of about 2.4:1... acctually, this is probably fairly close to optimum for a 3:1 diameter ratio, if you are seaking max power/overall length.
As a courtousy, could you spend the extra milliseconds and capitalize your letters, and spell out thanks? I spend hundreds of seconds on my posts, which I have posted over and over to previous newbs, just to help you; you can spend a few extra seconds to make your posts look nice. A bit of thought would be nice too - some of your posts are... elesive.
Also, why does your barrel have to be 3'?
Your 3' long, .5" diameter barrel with your 9.5" long, 1.5" diameter chamber will give you a ratio of about 2.4:1... acctually, this is probably fairly close to optimum for a 3:1 diameter ratio, if you are seaking max power/overall length.
As a courtousy, could you spend the extra milliseconds and capitalize your letters, and spell out thanks? I spend hundreds of seconds on my posts, which I have posted over and over to previous newbs, just to help you; you can spend a few extra seconds to make your posts look nice. A bit of thought would be nice too - some of your posts are... elesive.
Also, why does your barrel have to be 3'?
sorry
no my 3' long .75'' diameter barrel with my 9.5'' long 1.5'' diameter chamber, on burntlakte C:B ratio finder it said that would be a C:B ratio of 1:1
because for the thing said 36'' barrel was good(1:1) for my gun, with 9.5'' long chamber 1.5'' in diameter
and im saying how good would it be...like as in PSI or FPS?
no my 3' long .75'' diameter barrel with my 9.5'' long 1.5'' diameter chamber, on burntlakte C:B ratio finder it said that would be a C:B ratio of 1:1
because for the thing said 36'' barrel was good(1:1) for my gun, with 9.5'' long chamber 1.5'' in diameter
and im saying how good would it be...like as in PSI or FPS?
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boilingleadbath
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...and this is also the first time you have said .75"; re-read you origional post, and you'll find that it says "1/2 width".
I'm going to assume it was a typo (or bad wording) origionaly, in which case - with the bigger diameter barrel, it will indeed give you a 1:1 ratio.
Anyway, you are going about it 'wrong' - unless your bigest chunk of 1.5" pipe is 9.5" long, that is.
You don't enter a random chamber length, and determine how long your barrel has to be to take full advantage of it, because it is much better to design them <i>together</i>, finding the most effective use of your total length. (although 45.5" isn't a bad length now that I think about it.)
Incidentaly, you'd probably get more power/total length if you lengthened the chamber a bit - 50% wouldn't be over kill. (1.5:1 or 1.75:1 is probably about where you want to put the ratio, but it's really quite inexact)
As to power, I'm not really a combustion person, but I'll run some numbers here. Using the GGDT, I find that a marble (6.7 grams?) will be accelerated to a velocity of about 350 feet/sec (I used 45 psi as the pressure). Oddly, it also wants you to make your chamber about 18" long... a bit longer than I was figuring, and possibly wrong - but 14" isn't a bad idea. The benifit is only about 15 feet/sec anyway.
I'm going to assume it was a typo (or bad wording) origionaly, in which case - with the bigger diameter barrel, it will indeed give you a 1:1 ratio.
Anyway, you are going about it 'wrong' - unless your bigest chunk of 1.5" pipe is 9.5" long, that is.
You don't enter a random chamber length, and determine how long your barrel has to be to take full advantage of it, because it is much better to design them <i>together</i>, finding the most effective use of your total length. (although 45.5" isn't a bad length now that I think about it.)
Incidentaly, you'd probably get more power/total length if you lengthened the chamber a bit - 50% wouldn't be over kill. (1.5:1 or 1.75:1 is probably about where you want to put the ratio, but it's really quite inexact)
As to power, I'm not really a combustion person, but I'll run some numbers here. Using the GGDT, I find that a marble (6.7 grams?) will be accelerated to a velocity of about 350 feet/sec (I used 45 psi as the pressure). Oddly, it also wants you to make your chamber about 18" long... a bit longer than I was figuring, and possibly wrong - but 14" isn't a bad idea. The benifit is only about 15 feet/sec anyway.
awwww sweet thx for telling me! but i forgot to tell u this(if it makes a difference)i want my gun to be rifle size and be the best it can be for a rifle size gun(not cannon size with 3'' barrel diameter etc.), and ive heard from most people that 1:1 would out preform a 1.5:1 or a 1.7:1, but i dont know
thx for telling me all this info
EDIT:yes i did say 1/2'' sorry for changing on a dime,where did u get that GGDT?
thx for telling me all this info
EDIT:yes i did say 1/2'' sorry for changing on a dime,where did u get that GGDT?
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boilingleadbath
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<a href="http://www1.iwvisp.com/thehalls/GGDT/in ... l">GGDT</a>
Really, spread the news: Google is good.
Anyway, it's acctually for pnematic (air-powered) cannons. It <i>can</i> be used to give a (very) rough estimate of combustion preformance.
The acctualy diameter of the barrel doesn't matter in the consideration chamber:barrel ratio, and acctually... 1" isn't overly large bore.
They are right in a way. If you extend your barrel until it is long enough to give you a 1:1 ratio, it will indeed be more powerfull - you have more barrel in which to accelarate the projectile. Does that make sence yet?!
Really, spread the news: Google is good.
Anyway, it's acctually for pnematic (air-powered) cannons. It <i>can</i> be used to give a (very) rough estimate of combustion preformance.
The acctualy diameter of the barrel doesn't matter in the consideration chamber:barrel ratio, and acctually... 1" isn't overly large bore.
They are right in a way. If you extend your barrel until it is long enough to give you a 1:1 ratio, it will indeed be more powerfull - you have more barrel in which to accelarate the projectile. Does that make sence yet?!