Cold Weather Primer Test

H4831 said:
It looks like a lot of people missed the significance of your test.
That is, that even in the severe cold and even with ball powder, there is no appreciable difference between using a standard primer or a magnum primer.
I guess all the hand loaders who were reloading with every major type of smokeless powder for sixty years or so, before the magnum primers came on the market, and shooting in the most severest of weather, were not handicapped for lack of a better primer.
And the 30-30 type rifles that killed so many moose and elk in the years of the great depression, often in very severe cold, were just doing what they were designed to do.
Your test of the 30-30 I thought was quite significant, in that your load of 30 grains of 3031 powder is quite a light load, but still gave 2050 fps. A 30-30 was designed to give 2200 fps with 170 grain bullets and the older factory loads actually do give this velocity. An older du Pont reloading chart that I have, which is marked, "New Edition," shows 32 grains of 3031 for that velocity and that is close to what I got in summer weather. At one time the standard load for a 30-30 was considered to be 33 grains of 3031. I have used this load, but didn't test it over the chronograph. My point is that there must be little, if any, difference in 3031 powder, between summer and winter temperatures, judging by the good velocity you got with 30 grains in the 30-30.
I too, would like to see you test the 270 again.
What I really wish is that I could hand you some of my old war surplus H4831 to test. With my 24 inch Sako 270, 60 grains of that powder with 130 grain bullets, gives me 3078 fps, while their "newly" manufactured H4831 powder from the 1970s gave 2960 fps. It wouldn't surprise me a bit if their H4831 is now slower yet, giving lower velocities, which would correspond closely with the figures of most of your 270 readings.
By the way, the cold in no way should affect the lead in wires to your chronograph.
Bruce
Click to expand...

I don't shoot the 94 very often, and when I do I've been using cast bullets, so I've never worked up a good jacketed bullet load for it. Therefore I was uncomfortable going straight to 32.0 grs of 3031, a load which Ken Waters considered more suitable for bolt guns, and potentially increasing the pressure even more with the use of a magnum primer. It does appear that 31.0 grs would have been perfectly safe though.

Its cold (-35) and calm this morning, but after today the temperature will moderate, and this late in the winter its hard to know if we'll have another cold snap or if we'll just be in the mid to low -20's till the beginning of May. If the planets align correctly and it gets cold again, I will definitely re-shoot the .270 and the .222 Magnum.

With respect to the effect temperature has on conductivity, this from Wikipedia . . .

"Temperature dependence
Main article: Electrical resistivity and conductivity#Temperature dependence

Near room temperature, the resistivity of metals typically increases as temperature is increased, while the resistivity of semiconductors typically decreases as temperature is increased. The resistivity of insulators and electrolytes may increase or decrease depending on the system. For the detailed behavior and explanation, see Electrical resistivity and conductivity.

As a consequence, the resistance of wires, resistors, and other components often change with temperature. This effect may be undesired, causing an electronic circuit to malfunction at extreme temperatures."

Now while its not spelled out, I take this as meaning that the conductivity of wire decreases in extreme cold.
 
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Thanks for testing this Boomer. I have also done my own cold weather tests and as you know that's the best way to figure things out.

Regarding "big" cases, I fireformed 100 338 lapua cases with 89 gr imr7828 and 250gr interlocks and a zip lock bag full of primers, half of which were regular large rifle primers, in -34c actual temp and they all went bang and I noticed no difference between magnum and normal.

I did not chronograph them as I was fireforming so I can't speak to fps changes but I do know they all went bang and there were no hangfires.
 
Boomer said:
I don't shoot the 94 very often, and when I do I've been using cast bullets, so I've never worked up a good jacketed bullet load for it. Therefore I was uncomfortable going straight to 32.0 grs of 3031, a load which Ken Waters considered more suitable for bolt guns, and potentially increasing the pressure even more with the use of a magnum primer. It does appear that 31.0 grs would have been perfectly safe though.

Its cold (-35) and calm this morning, but after today the temperature will moderate, and this late in the winter its hard to know if we'll have another cold snap or if we'll just be in the mid to low -20's till the beginning of May. If the planets align correctly and it gets cold again, I will definitely re-shoot the .270 and the .222 Magnum.

With respect to the effect temperature has on conductivity, this from Wikipedia . . .

"Temperature dependence
Main article: Electrical resistivity and conductivity#Temperature dependence

Near room temperature, the resistivity of metals typically increases as temperature is increased, while the resistivity of semiconductors typically decreases as temperature is increased. The resistivity of insulators and electrolytes may increase or decrease depending on the system. For the detailed behavior and explanation, see Electrical resistivity and conductivity.

As a consequence, the resistance of wires, resistors, and other components often change with temperature. This effect may be undesired, causing an electronic circuit to malfunction at extreme temperatures."

Now while its not spelled out, I take this as meaning that the conductivity of wire decreases in extreme cold.
Click to expand...

This is from above. "Near room temperature, the resistivity of metals typically increases as temperature is increased,"
This states that the resistance of the wire conductor increases as the temperature rises. Therefore, as it gets colder the resistance is less=less loss of current in the wire.
 
Metals all fall under the classification of PTC's, which drop in resisitance to electrical flow as temperature drops.

As has been stated, many semiconductors and electrolytes are NTC's, which are just the opposite...a drop in temperature increases resistance.

You should experience no issues with the conductivity of those leads [wires] in cold temps.

Regards, Dave.
 
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