Reloading in a Vacuum.....

[45_auto]

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.

Those of us who reload in a vacuum have kids who shoot one hole groups at 320 yards and quarter size groups at 640 yards with old 700's.

 

[dmazur]

I had a chemistry teacher, many years ago, who referred to some of the class as possibly having developed a vacuum between their ears, based on their test scores...

So, I have tried to make sure I don't have a vacuum in that location when I'm reloading. Other activities may be more tolerant, but not reloading.

 

[Fryerpower]

Yes, google "firing underwater".

A cartridge will fire in the absence of oxygen.

Below is the answer to the question I was asking. I wanted to know if the air in the cartridge was required. I was not asking if there had to be air outside of the cartridge.

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.

-Jim

 

[pseudonymity]

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.

I would think that it would be just the opposite - in a vacuum your groups would be lousy with typical bullets shot out of a rifled bore.

The pressure of the air passing over the bullet combined with the rotational energy from the rifling is what makes the bullet stable. The air pressure is greater than the imperfections in shape and density in a bullet. I think a bullet would only be accurate in a vacuum if the pressure as it leaves the barrel is absolutely uniform on the base of the bullet. If the bullet is not exactly concentric in the bore, the spin from rifling would tend to increase tumbling like an off balance washing machine.

I think in a vacuum the best accuracy would come from a perfectly round, uniformly dense ball fired from a smooth bore. Any physics wizards on here that can check my assumptions? Maybe I am way off base.

 

[MErl]

spin stabilization doesn't depend on air to work but it also really isn't needed without air resistance. It would still be desired to stop the bullet from tumbling due to imperfections when it left the bore. Bullet would still fly in the proper arc and hit the right spot but might hit sideways without spin.

You may be right on the smooth bore/round ball though because it could be made with less variation.