Can the powder burn be improved?


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gamestalker
February 20, 2011, 04:06 PM
I've entertained a thereroy for a long time regarding certain cartridges and powder charges. An example of what I referrng to is the 45 LC. With an avergae powder charge the powder is not sifficient enough to provide a dense load and thus the powder lays on the wall of the case when it is fired. This causes two things to happen, one is the case ends up blackened on one side, and the other is poor or delayed ignition which causes inconsistent velocities. My thought on this is, would it improve ignition if the case was charged with nitrogen, or CO2 to inhibit oxygen during the bullet seating process. I know that some hand loaders will use dacron and other fillers to eliminate oxygenated space which works quite well, but I wonder if inhibiting the oxygen with one of the above gases would be effective?

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rcmodel
February 20, 2011, 04:37 PM
No, it would not.
Just like a solid fuel rocket engine in outer space, smokeless powder makes it own oxygen when it burns.

The smoked case is not due to the powder laying on one side or lack of burn anyway.

It is due to the cartridge laying on the bottom of the chamber.
Gas leaks past the case mouth before enough pressure can develop to expand the case fully and seal the chamber. SO, the top of the case likely gets fouled more then the bottom of the case where it is in contact with the chamber wall.

You can reduce the case fouling by increasing the pressure of the load.
Light loads smoke cases way worse then full power loads.

rc

critter
February 20, 2011, 05:27 PM
More crimp can help also as it lets pressure build (thus expanding the cases) earlier.

brickeyee
February 20, 2011, 06:09 PM
I know that some hand loaders will use dacron and other fillers to eliminate oxygenated space which works quite well, but I wonder if inhibiting the oxygen with one of the above gases would be effective?

Dacron and other fillers are used to keep the powder in the bottom of the case for better ignition, not displace air in the cartridge.

Smokeless powder uses nitrocellulose as the base, and sometimes some added nitroglycerin for double base powders.

These materials do not 'burn' in the normal sense of combining with oxygen.

They rapidly break down into a much larger volume of hot gases to drive the bullet.

The powder does not require any oxygen to break down.

Nitrocellulose and nitroglycerin are both 'under-oxidized' as chemicals.
They do not contain sufficient oxygen to carry all the gases generated to a stable state.

Flash suppressors are added to the powder to try and supply more oxygen and allow the hot gases to actually oxidize in the barrel, reducing the muzzle flash when the hot gasses hit atmospheric oxygen and finish burning to stable compounds.

Adding any gas to the shell is not going to have any significant effect, since it is not required for the breakdown of the powder to gasses.

Using a small piece of Dacron to hold the powder against the base of the shell works in large cases when the load does not adequately fill the case.

RidgwayCO
February 20, 2011, 09:06 PM
Another solution is to use a bulkier powder. My plinker .45 Colt loads use a 250gr LRNFP bullet over Trail Boss powder. TB fills the case nicely (with NO compression of the powder), generates satisfying velocity and accuracy, and leaves minimal exterior soot on the case.

Be advised, Trail Boss is not a slow-burning powder. I've read it's burning speed is close to Green Dot. According to Hodgdon, the reason you don't want to compress TB is because its physical geometry (think small green Cheerios) contributes significantly to its burn rate. Break the little donuts (through powder compression) and bad things happen to the burn rate...

FROGO207
February 21, 2011, 12:31 AM
Yep upping the pressure on 45LC loads can create bad problems in older firearms or the reproductions of same while just the Rugers can handle slightly higher pressures.
The others beat me to the needed info, additionally I also use Trail Boss in my Uberti and it works extremely well.

Sunray
February 21, 2011, 01:19 AM
"...Can the powder burn be improved?..." No. The burn rates of smokeless powders are created by the chemicals used.
Like brickeyee says, fillers are there to keep the powder against the primer hole. They do nothing to the burn rate.
"...case was charged with nitrogen, or CO2..." How are you planning on putting a gas in and keeping it there while you seat the bullet?
"...smokeless powder makes it own oxygen when it burns..." So does BP.

ljnowell
February 21, 2011, 02:09 AM
Yep upping the pressure on 45LC loads can create bad problems in older firearms or the reproductions of same while just the Rugers can handle slightly higher pressures. The others beat me to the needed info, additionally I also use Trail Boss in my Uberti and it works extremely well.


I guess thats true if you consider 2-3x the pressure a "slightly higher" amount.

Arkansas Paul
February 21, 2011, 07:05 PM
I guess thats true if you consider 2-3x the pressure a "slightly higher" amount.


Aint that the truth. I've shot some stuff in my Blackhawk that's downright scary! True, they're not always the most accurate. They sure are fun though.
You were right too amigo. 2400 is great stuff. I use it almost exclusively for heavy loads now.

gamestalker
February 21, 2011, 07:26 PM
You guys miseed my point. I'm totally aware of smokless powders properties which is why I asked if further inhibiting oxygen, not adding it, would improve a poor burn such as what happens if the powder isn't pushed against the flash hole with a filler. I've fired loads that were using smaller charges of faster burning powders, and the smokey wall disappears if I first hold the gun straight up allowing the powder to settle against the flash hole, and then lower is slowly so the powder is primarily against the flash hole. And regarding how to get a gas into the case is not part of the question. I never said I was trying to find a way to do this, I only asked what effect would it have on the efficiency of the powder burn, not change the rate of burn. As was pointed out, smokless powders don't need additional oxygen to burn, and actually don't produce the intended burn unless they are deprived of an oxgenated enviroment.
This post was just for fun and shouldn't be considered in any manner except in therory.

RidgwayCO
February 21, 2011, 07:56 PM
If we're talking theory, one of the more interesting articles I've read was by Elmer Keith (surprisingly enough...) where he talked about experiments with cartridges where the primer fired its charge into a long tube that fed to the front of the case, just below the bullet. The powder column then burned from front to back which supposedly produced a much more even burn and provided a significantly higher kick to the bullet without higher pressures. As I remember, the powers-that-be decided that the cases were too much trouble to produce in return for too little payback. I found the theory interesting though.

ljnowell
February 22, 2011, 02:33 AM
Aint that the truth. I've shot some stuff in my Blackhawk that's downright scary! True, they're not always the most accurate. They sure are fun though.
You were right too amigo. 2400 is great stuff. I use it almost exclusively for heavy loads now.
__________________


2400 seems like it was made just for heavy 45 colt loads, doesnt it? I keep at least 8lbs of it on hand because of that . Well, that and its my go to powder for full power 357 magnum also. It seems to burn really clean in that cartridge too, and make great accurate powerful loads.

brickeyee
February 22, 2011, 03:25 PM
and actually don't produce the intended burn unless they are deprived of an oxgenated enviroment.

Not needing is not the same as "don't produce the intended burn unless they are deprived of an oxgenated enviroment."

It does not matter.

The secondary oxidation of the hot gases is way to slow to have any real effect.

The greatest improvement in efficiency comes from higher pressure and making sure ALL the powder it ignited quickly (before it is spread to far from the hot primer flash to ignite correctly).

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