powder "burning dirty"

A

alinwa

oft dis'd member
Opinions please....

WHAT DOES THIS PHRASE MEAN, "burning dirty?"

I see reference to powder burning dirty nearly every day, I've never experienced anything I'd describe this way.

al
 
I'll try! Residue in the barrel after firing. More noticeable with BR shotguns like after using Red Dot, etc.
Centerfire
 
actually when powders burn at lower than thier "sweet" spot they often burn incomplete or dirty.

i don't know all the sweet spots,(actually few) but take any powder and shoot it at a pressure that is under a "resonable" pressure for the bullet /cartridge, and you may get a dirty bbl.
i can shoot cast bullets at 1600 fps in a 308 with a clean burn using something like imr4227, and get a clean burn with a 168 match with 8208 in the same 308 , but try 4064 with the cast at 1600 and the chamber pressure is so low you get a poor burn...dirty.
on the other side of the coin there have been some import milsurplus powders that just plain burned dirty at what appeared to be a good load. classic example was the mil surplus 2200. with a reasonable load in a 223 with a 55 gr bullet (short range high powder load), 20" bbl 3100 fps it left the bbl dirty..black even tho the pressure was up in the 50's.



mike in co
 
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sweet spot

powders do have an often narrow pressure band where the burn clean, that said different primers develop different pressures there is a chart with most included i think i saw it at reloaders nest but br primers were close to if not the lowest they also had the highest cold failure rate
 
Al; i think they mean that some powders burn dirtier than others. When i shot the 308 Baer and used Reloader 25 with the 240 Sierras and pushed a wet patch through the bore and let soak it would take at least 3 times to start to get blue on the patches. When i switched to H 4831 shortcut, the second patch would be blue. I consider the 4831 to be cleaner. The same thing with H 4350 on the 300 WSM. It could be because of pressure but all loads are pretty close to the max. This is after 8 sighters and 10 Record shots. Matt
 
For me, the term dirty, when used to describe how a powder burns, refers to how much powder fouling is left behind, sort of a ratio of shots to cleaning time/effort. 133 is the cleanest burning 6PPC powder that I am aware of, and Reloader 10X one of the dirtiest. Beyond how much powder fouling is produced is how hard it is to remove.
 
I have always thought it related to the relative powder characteristics after burn. For example, I try to avoid using Varget, because it leaves a lot of residue behind that takes some cleaning out whereas VV N550, one I use regularly burns very completely & easily cleans with a quick dose of upper engine cleaner.

I suspect that it might relate to the quantity & makeup of the inhibitor used in some powders to standardize the burning rate to spec.

John
 
clean burn

more like excess fuel in an engine you get black soot from the leftover that is burning with depleted oxygen in the exhaust , maybe going to the imr and .2 to .4 less will put you at the same point but cleaner it is a little faster
 
better anolagy

when you light acetylene and dont have enough oxygen or pressure you get nasty soot that sticks to everything it is a plastic gunpowder uses a similar chemical compound that if not blown out of burned completely is a sticky mess the nitrocellulose powders (single base) are more prone to be "dirty" out of their Ideal pressure band
 
I've always thought of clean vs. dirty powders as it relates to how much carbon it produces. And a good indication of this is how dirty the fired case necks are as they come out of the chamber. I use a lot of VihtaVouri N133 & N135 and case necks come out very clean. Have used some ball powders ( don't use them anymore), and the case necks are ugly black after firing. Varget is also a favorite and fouling is a little more than VV, but not nearly as bad as the ball powders. Just borescoped one of my Bartlein barrels (6ppc) with my Hawkeye, and after 350 rds. fired, minimal carbon fouling. Varget, would require carbon removal long before that. "The Benchrest Shooting Primer" has a very good article on this very subject, beginning on page 211, titled " .223 Remington Match Rifle Data". Note the references to 748, BLC-2, 380 & 414, (all ball powders) with notes: " Fired cases- necks and shoulders very sooty-and difficult to clean". For 380:"very difficult to clean". 414: "severly sooted".
 
Shortly after IMR 7828 came out a guy who was perpetually looking for the magic powder/load for his .243 Win rockchuck rifle showed up at the range with various 7828 charges behind 85 gr Sierra HPBT's. I'm not sure what the inside of the barrel looked like, but he ended up with a pile of nitrocellulose "popcorn" under the muzzle of his rifle. I'd call that likely dirty. Those loads had to be WAY below the optimum pressure for 7828. So much for powder all burns within an inch or so of the case mouth too.
 
So much for powder all burns within an inch or so of the case mouth too.
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Larry I don`t know this to be true, but I`ve been told by what I feel are reliable people the deal is "all the powder that is going to burn, burns within the 1st inch or so of the barrel". That does not mean "all" the powder is burnt, just that all the powder that can burn with the oxygen that the chemical process produces does. The gas that is produced is still full of extremely hot unburnt flammables that re-ignite upon contact with the air and a fresh oxygen supply showing as "muzzle flash".
Again, I have no proof, this is just what I`ve been led to believe occurs.
 
ever see a 50 ae desert eagle the powder is still burning at the muzzle big flame thrower and the shells are clean as if they came out of a tumbler
 
Joe S said:
Larry I don`t know this to be true, but I`ve been told by what I feel are reliable people the deal is "all the powder that is going to burn, burns within the 1st inch or so of the barrel". That does not mean "all" the powder is burnt, just that all the powder that can burn with the oxygen that the chemical process produces does. The gas that is produced is still full of extremely hot unburnt flammables that re-ignite upon contact with the air and a fresh oxygen supply showing as "muzzle flash".
Again, I have no proof, this is just what I`ve been led to believe occurs.
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In black powder this is true but not smokeless powder if you fire a muzzle loader the recoil is hard and sharp the recoil from say my 1903 is a pushback the powder burns for a long time in comparison to the black powder which explodes not so much burns
 
swmft said:
In black powder this is true but not smokeless powder if you fire a muzzle loader the recoil is hard and sharp the recoil from say my 1903 is a pushback the powder burns for a long time in comparison to the black powder which explodes not so much burns
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Could you cite some support for this please?

al
 
swmft said:
In black powder this is true but not smokeless powder if you fire a muzzle loader the recoil is hard and sharp the recoil from say my 1903 is a pushback the powder burns for a long time in comparison to the black powder which explodes not so much burns
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True BP is said to "detonate" and smokeless "burns" but the rate of time smokeless burns is controled buy the deterents added to the powder and the pressure the powder subject to. You can change the burn rate by simply altering the pressure it is subject to.
Smokeless burns very fast in an inclosed chamber but can only burn as long as oxygen is present. Once it uses its oxygen it flames out. The powder granuals found in the snow or on a floor infront of the line is from the unburnt powder that didn`t reignite due to the absence of enough pressure to keep it going once it left the muzzle. It is similar to lighting a pile of black powder and another of smokeless on your driveway. The BP will "poof" and be consumed, the smokeless will be harder to ignite and leave some residue behind after burning.
Recoil means nothing inre to how powder burns other then that it did enought to push a bullet out the barrel. Your rifle moved from the force exerted by the bullet being pushed foreward with a touch of recoil added for the force of the powder gas wt and velocity in.
 
http://www.ctmuzzleloaders.com/ctml_experiments/bp_burning/bp_burning.html

http://www.frfrogspad.com/intballi.htm http://www.alliantpowder.com/getting_started/safety/storage_handling.aspx

these should answer most of the questions as for the way smokeless and black powder burn the are both self contained reactions set off by catalysts black powder is more reactive at atmospheric pressure than smokeless and smokeless requires the heat and pressure to liberate the oxygen for the reaction to be efficient

black powder is a low explosive smokeless is a propellent remember the flash for the old pictures 1 gram of blackpowder burns in about .15 seconds in open air puff same amount of 4895 about 1.5seconds try it but not on your bench ,dont want your wife blaming me for burning the house down
 
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