Cold weather and ammo

[SA John]

It's late at night and my back is killing me. I thought some of you might like to read about a test I ran back in 1980 with regards to cold weather and its effect on ammo performance. I had read an article about polar bear hunting with Fred Bear the archer and his backup gun hunter. Earlier in his carrier Bear swore that he never had a gun backup. In time he softened and admitted to having a rifleman off camera. In the article I read in the late 70s the two men were talking about how the cold might effect the primer and powder in the rifleman's .375 H&H. Temps where they were hovered around -20 to -40 degrees F. I have forgotten what they concluded, but it got me interested in setting up my own experiment with a 7.5" .44 Mag SuperBlackhawk. I had a 240gr cast SWC load that used 22.0 of Hercules 2400. This was before Alliant bought them out. That load was the standard of the day. It gave me a very accurate 1387fps on average when fired during the summer months when the silhoutte season was on. I would say the average temperature was around 75-80 degrees when I chronoed them. I have always kept reloading info from the very start of my reloading as a teenager. All the numbers here are taken from notes written back in 1980.

So I had a good bear load when the air temp was normalish for humans. I wanted to see what could happen up in Alaska if a bear became a problem in really cold weather. Into the freezer chest went the fully loaded Super Blackhawk. I let it sit over night at a temperature of -24 F, and in the morning before the outside air had a chance to get too warm, I wisked the revolver out the back door and shot all 6 rounds through my chrono that had been set up and recorded the following speeds: Shots one through six - 1211,1237,1248,1231,1275,1266fps. That's an average of 1245fps which is a reduction of 142fps from the warm gun, warm air 1387fps average. A little unscientific, but fun for a young 23 year old trying to learn something.

I think a bear shot between the running lights with a 240gr LSWC at the reduced speed of 1245fps wouldn't complain too much about the difference. I have stopped worrying about tracking down wounded Polar Bears with my .44 in the dark Artic night.

Hope you found this interesting.

SA John

P.S. I had to detail strip the damn gun after because of the tremendous amount of condensation that fairly poured out of the gun's innards as it warmed up. I had to get all the water out, it was a blue-steel gun. I won't repeat that experiment again with a blue gun.

 

[Patriot]

It's late at night and my back is killing me. I thought some of you might like to read about a test I ran back in 1980 with regards to cold weather and its effect on ammo performance. I had read an article about polar bear hunting with Fred Bear the archer and his backup gun hunter. Earlier in his carrier Bear swore that he never had a gun backup. In time he softened and admitted to having a rifleman off camera. In the article I read in the late 70s the two men were talking about how the cold might effect the primer and powder in the rifleman's .375 H&H. Temps where they were hovered around -20 to -40 degrees F. I have forgotten what they concluded, but it got me interested in setting up my own experiment with a 7.5" .44 Mag SuperBlackhawk. I had a 240gr cast SWC load that used 22.0 of Hercules 2400. This was before Alliant bought them out. That load was the standard of the day. It gave me a very accurate 1387fps on average when fired during the summer months when the silhoutte season was on. I would say the average temperature was around 75-80 degrees when I chronoed them. I have always kept reloading info from the very start of my reloading as a teenager. All the numbers here are taken from notes written back in 1980.

So I had a good bear load when the air temp was normalish for humans. I wanted to see what could happen up in Alaska if a bear became a problem in really cold weather. Into the freezer chest went the fully loaded Super Blackhawk. I let it sit over night at a temperature of -24 F, and in the morning before the outside air had a chance to get too warm, I wisked the revolver out the back door and shot all 6 rounds through my chrono that had been set up and recorded the following speeds: Shots one through six - 1211,1237,1248,1231,1275,1266fps. That's an average of 1245fps which is a reduction of 142fps from the warm gun, warm air 1387fps average. A little unscientific, but fun for a young 23 year old trying to learn something.

I think a bear shot between the running lights with a 240gr LSWC at the reduced speed of 1245fps wouldn't complain too much about the difference. I have stopped worrying about tracking down wounded Polar Bears with my .44 in the dark Artic night.

Hope you found this interesting.

SA John

P.S. I had to detail strip the damn gun after because of the tremendous amount of condensation that fairly poured out of the gun's innards as it warmed up. I had to get all the water out, it was a blue-steel gun. I won't repeat that experiment again with a blue gun.

That is so cool, and so 23 year old-ish. Kudos to you for giving it a go. Now I won't
have to do this experiment which was right at the top of my list of things to do!

 

[Dick]

I just love it when someone posts real data rather than rely on the myths and conjecture that surround so many gun discussions. Good job, SA John - and a rep point for you.

 

[MFP4073]

John,

Thanks for posting that. I enjoyed that tidbit of info!

 

[EC1]

One possible answer for the slow down might be the effect of density differences of the air due to the low temperature. Over the temperature range you mentioned, cold air approaches 15% higher density compared to the hotter air.