An other Noob question about powder temperature.

PepeLapiu

PepeLapiu

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Been lurking on and reading a few threads.

So warm powder will get your velocity up.
Wouldn't it be more advantageous to keep your ammo in a cooler or heat box to make sure your ammo is always at the same temperature? So you can eliminate that variable?
It seems I would build a little propane heater in a cooler that always keeps my ammo at a constant temperature. No?
 
I'm going to give this thread the benefit of the doubt that it was intended for this forum since many competitors do keep their ammo in coolers to try and keep it at a constant temperature.
 
Ha!
Okay. Been reading about long range shooting for a long time and this is the first I read about that.
Thanx.
 
Just keep the ammo in the shade and out of the sun as much as possible during the match.
Another temperature variable is the air temp as the day wears on and it gets cooking at around noon during summer. Warmer air means less resistance during the projectiles flight path causing high impacts if not corrected for at longer range.
 
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A cooler is perfect for storing ammo at the range. If it is real hot, I put a can or two op cold pop in there, as a heat sink.

In the winter, when testing ammo outdoors, I take ammo to range in a cooler with a 2 litre pop bottle of hot water in the cooler. When shooting, I put 5 rounds at a time in my shirt pocket. Body temp keeps the ammo at a "hot day" temp.
 
PepeLapiu said:
Been lurking on and reading a few threads.

So warm powder will get your velocity up.
Wouldn't it be more advantageous to keep your ammo in a cooler or heat box to make sure your ammo is always at the same temperature? So you can eliminate that variable?
It seems I would build a little propane heater in a cooler that always keeps my ammo at a constant temperature. No?
Click to expand...

Only thing I wouldn't do is have a propane heater anywhere near my ammo. Inadvertent bump of the cooler and a round falls against the heater.....?
 
Cold would make the air inside the cartridge denser wouldn't it? Therefore it would contain more oxygen and other stuff for the powder to heat up and cause higher pressures.
Of course we are splitting hairs here.
The long range guys here would know the answer to this as that is probably the only place you would notice the difference.
 
Heat makes the chemical reaction inside the cartridge happen faster.
Cold temperatures slow it down.
My dad tells me stories about going to hunt in Alaska when it was -50 C.
Said the slugs would virtually fall off the end of his shotgun. Thought he was probably exaggerating.
 
And btw, your ammo dorsn't require oxygen or air to detonate. You can fire a gun under water and it will still go off. Of course cycling the action and getting the bullet to go far are different stories.
Check it out on Youtube: guys shooting AK-47 or AR under water.
 
Ten four Gentlemen, just thinking of how engines work.
Cold air and gasoline make more horse power. Gunpowder contains enough oxygen to support combustion, just like nitro methane.
Speeding up or slowing down combustion depends on how much oxygen is present when combustion occurs. Hot air contains less oxygen than cold air.
Physics, cant get around it. I am probably not explaining this very well.
 
You pretty much have the gist of it except for the following:

snoopycda said:
Speeding up or slowing down combustion depends on how much oxygen is present when combustion occurs. Hot air contains less oxygen than cold air.
Click to expand...

The burning of gun powder is a chemical reaction which pretty much produces it's own oxygen for the combustion. If you open up a cartridge and pour the powder on a plate you can light it up. It will burn very fast but it won't explode as it would inside a barrel. And than in spite of the large amount of oxygen available around your plate. Same would happen with a stick of dynamite. You could hold a stick of dynamite in your hand and light it up. You will badly burn your hand and perhaps your forearm too. But it still won't explode and take out any of your fingers.
As the powder burns inside your barrel, it produces a bunch of gasses. One of those gasses is oxygen. And as the gasses are produced, they have nowhere to go. So the reaction basically pushes the bullet out of the cartridge and down the barrel to make more room for the gasses.

This chemical reaction, like pretty much all chemical reactions, occurs faster when warm. So the gasses are produced faster and the bullet travels faster.

Now maybe there are some minute gains in reaction when there is more oxygen available inside the cartridge. But this gain would be so minute as to never be observable and it wouldn't counter the effect of temperature on the reaction itself.
 
The premise described is sound until modern voodoo gets put into the mix. Some powders, like the Hodgdon Extreme vary very little in either pressure or temp over a very wide operating temp range. That is verified by chronograph and come ups to get on target at LR.

And of course, groups on paper.

Most F class shooters who shoot through the season have learnt to test over a wide range of temps including sitting in the sun (not a good idea but sometimes necessary). With the right tweaks, accurate and consistent results can be obtained.

For me, anything over 15C to 38C is good with the same load. I might retune for matches that go from 0C to 15C but that might be only 1 a year and I am getting a bit lasy to compete in the winter

Many powders are not that friendly.

Jerry
 
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