Reloading in a Vacuum.....

Hondo 60 said:

dropping powder would be an issue.

BECAUSE IT WOULDN'T DROP.

How do you get the powder to "fall" into the case?????

And then how do you keep it in the case while seating a bullet????

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Sucking out the air doesn't turn off gravity!

Am I still on the THR forums? Even if it was possible to create loads in a vacuum, once removed from the vacuum the casing would crush even if the bullet and primer was sealed in place. Now, loading cartridges with an inert gas could possibly have real world uses, maybe not for me, because without such extreme measures I still can not shoot as well as current equipment and technology allows. Lol

The capacity of my 30-06 case to the top of the neck is 67.6gr. I then fill this with 52.8gr powder and seat a bullet effectively eliminating the volume of air in the neck.

So discounting the neck for the time being the available air space in the case is 52.8/67.8 = 22% atmosphere in the case.

The atmosphere consists of 21% 0xygen so effectively you would want to remove 21% of 22% or 4.8% oxygen. A serious case of diminishing returns especially considering we have not factored in the exclusion of atmosphere due to a seated bullet which will drop the 4.8% even further.

Steve2md said:

My reasoning behind believing a vac would burn more completely, is that it would take slightly longer for the pressure within the case to build enough to push out the projectile, vs an atmos round, which would immediately begin to compress the air (o2 and N), increasing pressure. In the vac round, there is nothing to compress until o2 and Co2 are produced by the burn.

Things that make you go hmmmmm

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I don't know and ain't going to test it to find out , but a potential flaw in that theory is that smokeless powder burns more efficiently under pressure, so you would be starting out in the hole if you vacuum packed it. You might actually gain better performance by pressurizing cartridges instead of vacuum packing them. I'm not going to test that theory either.

Sucking out the air doesn't turn off gravity.

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Correct. Even our own president has said, "If you like your gravitational constant, you can keep it."

I'm not getting into the theory but wanted to point out that 29.5 micron won't be able to collapses a case & you can't get any more then that.

If you could create a pure vacuum inside a brass casing I am quite willing to bet it would collapse, and we quite often get more than 29.5 inches mercury atmospheric pressure, although that would be more than enough.

Cleftwynd said:

If you could create a pure vacuum inside a brass casing I am quite willing to bet it would collapse, and we quite often get more than 29.5 inches mercury atmospheric pressure, although that would be more than enough.

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I would take that bet. A cartridge case is a cylinder, and therefore the shape best suited to resisting uniform exterior pressure.

If cartridge cases had large, flat sides I would agree with you. An IMR metal powder can will absolutely collapse under 1 atm of pressure...I used to collapse metal cans for demonstrations in my science class.

On the other hand I also routinely drew down to near zero pressure inside a glass bell jar and it withstood the pressure just fine. There's not enough surface area relative to interior volume to collapse something as sturdy as a brass cartridge case. Really big stuff like artillery brass might collapse if made thin enough, but not normal rifle/handgun rounds.

1 atm = 32 feet of water pressure. Do brass cartridges collapse under 32 feet of water?

So in other words if you tried to vacuum out all contents from a brass cartridge to make it an absolute vacuum it won't collapse? I am curious as well, if someone had the equipment to conduct such a test I would like to see the results.

A true vacuum at sea level would be -14.7psi I HIGHLY doubt that would cause a high powered rifle brass to implode, in fact I would bet money on it. I see no advantages to a zero atmosphere cartridge, it makes little to no sense starting out with a negative pressure when a higher pressure is our goal. Low levels of humidity have little bearing on the performance of powder, temperature at the time of firing is a MUCH larger pressure/speed variation, if you wanted to get all super high tech with it some mechanism to control cartridge temperatures under sustained fire would be much more fruitful.

Theories and hunches are great but nothing beats experimental data. If it's your thing, and you can do so safely, carry out your experiment and let us know what happened.

Having said that, this one is a head scratcher for me. What is the suppossed advantage? The combustion of the gunpowder is independent of atmospheric oxygen. Having more of less of something in the immediate vicinity of a reaction when that something is not used in the reaction seems not likely to have any effect on the outcome. I read one of the earlier posts and it posited a more uniform combustion if there was no air in the cartridge case. What's the idea here? How would that make a difference?

Again, bottom line, go for it (safely) and let us armchair intergalactic space reloaders know the results.

Dan

lol. well, they'd fire, but there would be no "bang" in space....no sound in a vacuum....

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Actually, there would be a bang. The gasses generated by the powder burn would contain "bang"; but the sound would not carry as the gasses disperse in the vacuum.

Did you know there was a pistol on board during the moon landing?

You are partially right. The moisture in the air or humidity helps offer a medium for static charge to bleed off.

The dryness in the air will not allow the static to drain to any "ground surface" or equalize between two different surfaces negating the potential for a static discharge to occur.

In electronics, when the humidity is too low, air ionizers are employed to give the atmosphere a charged particle path for static to take to ground, albeit in a controlled manner.

For reloading, it's best on a concrete floor, no rugs, no styrofoam, no plastics, no shuffling of feet, no polyester shirts or pants (good old cotton).

I had to help insure our men and women in battle never had to deal with our missiles failing because some damn part got partially blown out by static and failed at the moment it was most relied on.

Carry on.

Falling in a vacuum? Not a problem, in the absence of an atmosphere as in a vacuum the powder will fall faster. Then there are those things I am not curious about, the benefit of a vacuum and reloading, if I was curious and if I wanted to know if my reloads were sealed at the neck and primer I would place the loaded ammo in a glass jar filled with water, THEN! I would remove the atmosphere in the top of the jar and then watch for bubbles escaping from the case.

Then there is that part where ‘How would I know I had removed the atmosphere above the water inside the jar?

F. guffey

Thoughts?

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I have access to a vacuum chamber large enough that you could set up a reloading bench in but I think you will die before you could load any.

So does gun powder provide it's own oxygen for the fast burn oxidation event or does it need that little bit of oxygen in the case?

Jim

So does gun powder provide it's own oxygen for the fast burn oxidation event or does it need that little bit of oxygen in the case?

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Excerpt from link -

answers.yahoo.com

You need oxygen for a combustion explosion. However, there are many chemical reactions that do not need oxygen that can release enough energy for an explosion. Nitroglycerin, the active ingredient in dynamite, is an example.

And another -

Thermobaric weapon

Thermobaric explosives rely on oxygen from the surrounding air, whereas most conventional explosives consist of a fuel-oxidizer premix (for instance, gunpowder contains 25% fuel and 75% oxidizer).

My understanding is that any air which might happen to be inside a cartridge during manufacture is not required for function.

A cartridge will fire in the absense of oxygen.

Yes, google "firing underwater".

Theories work fine if you have infinite funds to play with--like our tax dollars. In the real world loading works just fine the way it is. My son shot a one hole group at 100 yds last month. Just how much better does one want to get? Other son shot a quarter size group at 320 yds using my old 700.

Sure, Vac reloading is not easy enough to be something we should strive for, but this conversation may spawn new ideas that could make us better overall reloaders

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You bet it has! Forget about reloading in a vacuum, I want to shoot some groups in a vacuum. Less resistance on the bullet and no wind at all, bet that tightens up the groups.