complete powder consumption for reduced muzzle flash

[cpileri]

Learned Sirs and Ma'ams,
Is there any way to predict or calculate what loads and of what powder will burn 100% in a given barrel length?
Or, is there any extensive source for this info, even if derived experimentally?

I will be taking care of some predating coyotes in the evening/dark, and will be using an 8mm Mauser sporter carbine; that has a night vision scope on it. I want to keep the flash to a minimum so that the scope dimming is not too limiting (or if it can be eliminated...)

The rifle has no flash hider, and no threaded barrel; and I dont want to go that route- esp if I can achieve it with proper load data.

I know that I can use "the Load" (13gr Red Dot and normal-for-caliber-weight cast bullets) and other reduced or "cat sneeze" loads using fast powders. I will use these loads only if a load that approximates full power, range, and trajectory cannot be achieved with complete powder burn.

Many Thanks,
C-

p.s. if someone is willing to run a Quickload calculator for me, how i should phrase the question so the program can work with it? What i mean is,
would it be able to tell me an answer in a question phrased with barrel length the variable, or with powder charge the variable? or something else?
examples:
Multiple-Powder charge variable: With 8mm Mauser chambering and 200gr projectile, and 20" .323 barrel, how much of each powder gives 100% burn?

Single Powder charge variable: With 8mm Mauser chambering and 200gr projectile, and 20" .323 barrel, how much of IMR-4895 gives 100% burn?

Barrel length variable: With 8mm Mauser chambering and 200gr projectile, and 45gr of IMR-4895, how long a .323 barrel is needed to give 100% burn?

 

[rcmodel]

Muzzle flash is more a product of the superheated & high pressure powder gases coming in contact with free oxygen in the air then it is with incomplete powder burn.

If you push an 8mm to full muzzle velocity, you will have flash, regardless of the powder used.

With that said, faster burning powder like IMR-4198 or IMR-3031 will give less flash then slower powders like IMR-4350, or 4831.
But not because it all burns, any more so then a slower powder.

It is because bore pressure is less at the muzzle by the time the bullet is released.

rc

 

[denton]

rcmodel has it right. Muzzle flash in rifles is not burning powder, it is glowing hot burned-out powder. And when it hits the air, it also re-ignites.

 

[cpileri]

Thanks, Sir!
Is there any velocity in particular, or any way to know which variables can conspire to reduce the plasma-esque, "hot gas hitting the atmosphere" effect?

If any Quickloaders are out there and willing (it could happen!) my variables would be: powder h4895 (*) at 41.5-45.5gr (if I had to pick one, lets say 45.5gr for best pressure ); 20" bore, 200gr .323 bullet Barnes XFB (**)
, and 3.18: OAL. pressure would be 50-52000 psi unless I need to go higher (to max 57K) to get what i am after.


(*) Barnes lists BL-C(2) as faster, but burns dirty so i wont be trying it first at least.
(**): or a cast lead 170gr FP, but then the velocity would be reduced to 1600fps or less, with associated reduced powder/charge, and OAL 2.61, and way reduced pressure. So never mind that one for now.

Thanks!
C-

 

[Walkalong]

Quickload will predict the amount of powder burned in the barrel.

Powder makers use coatings on some powders to reduce muzzle flash as well. That will make more difference than fast or slow.

 

[denton]

Well, military artillery used to (and may still) mix about 10% black powder in the propellant to conceal muzzle flash. Seems a bit extreme, though.

Longer barrels tend toward less flash, of course. I don't know what you can do by juggling load parameters to get less flash. If you burn X grains of powder, you're going to get X grains of propellant gas, and I think that no matter what you do you're going to have re-ignition.

It would be entirely possible to chemically add more oxygen to the propellant mix, but that would not be a good idea. You want the propellant to be a little fuel rich. If you make it fuel lean, it will eat away the innards of your gun faster. Think "burned valve" in an auto engine that is running too lean.

 

[jmorris]

A supressor does a good job at reducing muzzle flash. I have a 10.5" .223 that with a suppressor has less flash than a crank of the flint on a Zippo.

 

[cpileri]

Well, Sure a suppressor would be great. but no muzzle devices on this one at this time.

I have been looking into H322 powder. Looks like alot of 308 WIn and even 303 British loads use this powder, though not so much 8x57mm. I speculate that popularity of the 308 vs the 8mm for reloading purposes has more do do with it than lack of suitability of H322 to the 8mm case. Am I wrong in my thinking?

I'll post more later, but the only reference I could find for 8mm Mauser with H322 and heavier bullets was from mausershooters; excerpted from Lee's Modern Reloading using jacketed bullets up to 170gr, which was loaded between 34-39gr from Hogdon (with 168gr projectiles) and 39 - 44gr of H322 (to max V of 2500-ish) from Lee. Then a conspicuous absence of any "fast-medium" powders fro the 200+gr projectiles. It looks like folks just stopped trying the "faster"-medium burn powders in 8mm. Probably because velocity falls off too much at safe pressures. but that's OK with me for this application. I just dont have any data to go on.

so I am checking around. remember this is for reduced loads.
C-

 

[rcmodel]

Is H-322 a good choice for reduced loads?

Not as good as H-4895.
http://www.hodgdon.com/PDF/H4895 Reduced Rifle Loads.pdf

rc

 

[Strykervet]

There are lower flash powders, but none I know of are zero flash. No matter the load.

As far as flash hiders, I had to get those AAC Blackouts to use a suppressor. Never seen one work that well, 7.62 was just a very light puff. They make the non-mount version, but they are just as expensive.

But an actual suppressor will solve pretty much most of it if not all of it.

 

[brickeyee]

it is glowing hot burned-out powder. And when it hits the air, it also re-ignites.

Not even powder, just gasses and products of the powder breaking down.

Smokeless powder uses nitrocellulose as its main ingredient.

The powder does not 'burn' in the conventional sense of oxidizing.
It breaks down rapidly into a large volume of hot gasses, and in confinement produces high pressures.


Nitrocellulose is well know to be 'under oxidized' since the molecule does NOT contain enough oxygen to bring all the gasses generated to a stable state.
Chemicals added to reduce muzzle flash typically produce extra free oxygen.

This allows the hot gases to oxidize to a stable state sooner, and reduces the muzzle flash.
It is not that the powder "re-ignites"
But that the hot gases on contact with atmospheric oxygen (and nitrogen to a lesser degree) release more energy as they react to form more stable compounds.
And yes it can be hot enough and reactive enough to tear apart even an N2 bond, though oxygen is easier to break up and then react with.

It does represent the final burning (as in oxidation) of the hot gasses.
They are already so hot that 'ignition' is not an issue.
Thousands of degrees is all you need.