Myth-Busting Powder Burn Rate vs. Barrel Length

Ganderite said:
Powder does not contain enough oxygen to burn all the propellant. So propellant is always expelled at the muzzle. Might be a solid, might be in gas form. If gas, it sometimes ignites when it hits the air (oxygen). This flash is a foot or so in front of the muzzle. It might also produce an extra loud bark of its own.

Some powders (most) contain additives to reduce muzzle flash. Some to a better job then others.

Muzzle flash has nothing to do with un-burned powder or lost energy.
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This is exactly what is happening.
With very few exceptions, most pastes are formulated with a slightly negative oxygen balance. The flash is produced from the super heated gases coming into contact with oxygenated air.

When manufacturing detonating formulations I keep as close to neutral ( balanced) or slightly positive.

A variation of sodium is sometimes added in small amounts to either the paste or to a surface coat as a deterrent to reduce flash. In higher ratios it will directly affect the VOD's
 
1-trident-1 said:
so, would the point @ which peak pressure occurs affect the rate of throat erosion?
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No. For practical purposes, peak pressure for a given caliber is always reached at about the same spot.

Throat erosion is proportional to the amount of powder (sandpaper effect of all that powder getting basted through the throat and flame temperature. Some powders burn a lot hotter than others.
 
Ganderite said:
Powder does not contain enough oxygen to burn all the propellant. So propellant is always expelled at the muzzle. Might be a solid, might be in gas form. If gas, it sometimes ignites when it hits the air (oxygen). This flash is a foot or so in front of the muzzle. It might also produce an extra loud bark of its own.
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Expatriot said:
This is exactly what is happening.
With very few exceptions, most pastes are formulated with a slightly negative oxygen balance. The flash is produced from the super heated gases coming into contact with oxygenated air.
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Alliant's website disagrees

Oxygen from the air is not necessary for the combustion of smokeless powders since they contain sufficient built-in oxygen to burn completely, even in an enclosed space such as the chamber of a firearm.
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Some German shooters when they try rifle loads with slow powders load with 1/2 grain increments and in the late evening they observe the muzzle flash....they shoot and observe when it disappears and when increasing the load it Reappears again they back to the previous...they say that when they have no flash they exploit to the max the powder capacity and have low deviation
 
ago1 said:
Some German shooters when they try rifle loads with slow powders load with 1/2 grain increments and in the late evening they observe the muzzle flash....they shoot and observe when it disappears and when increasing the load it Reappears again they back to the previous...they say that when they have no flash they exploit to the max the powder capacity and have low deviation
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Thats a Fairly Scientific Method for Sure - I would use that for SURE ! Especially with SUPERFORMANCE powder ! :p RJ
 
Was shooting some H335 ball powder in my 16.1" 223 the other day. Unreal muzzle flash. 86% powder burn according to QL
 
todbartell said:
Was shooting some H335 ball powder in my 16.1" 223 the other day. Unreal muzzle flash. 86% powder burn according to QL
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Question, what brand and type primer were you using?

I'm old school and use magnum primers with any double base ball powders because they have more deterrent coatings than single base powders.

My practice load for my AR15 carbine is 25 grains of H335 with Hornady 55 grain FMJ bullets and do not notice a big muzzle flash when shooting.
 
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Ganderite said:
No. For practical purposes, peak pressure for a given caliber is always reached at about the same spot.

Throat erosion is proportional to the amount of powder (sandpaper effect of all that powder getting basted through the throat and flame temperature. Some powders burn a lot hotter than others.
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so we need a chart of hottest to coolest burning powders.
 
1-trident-1 said:
so we need a chart of hottest to coolest burning powders.
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Most shooters don't shoot enough to wear out a barrel.

Target rifle shooters do. They typically burn and replace a barrel ever year or two. A blue barrel lasts about 2500 rounds. A stainless, double that.

Back in the 30-06 days (Camp Perry) the Army team loaded 4350 and the Air Force use 4831. The Air Force barrels lasted twice as long. IMR reported that 4350 burned much hotter.
 
bigedp51 said:
Question, what brand and type primer were you using?

My practice load for my AR15 carbine is 25 grains of H335 with Hornady 55 grain FMJ bullets and do not notice a big muzzle flash when shooting.
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CCI 400

When switching to 55gr bullet, the % of powder burnt in the 16.1" barrel goes up to 94%
 
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