Caution in the cold

[Cold Trigger Finger]

At the risk of starting something.
But because I've experienced the results I will share this.
With this batch of cold temps in the lower 48. Some may want to brave the cold and see how their rifles and other firearms handle the cold. True , Cold . 40 below ambient type temps.
Rifle barrels, being made from round , steel alloy . they contract in the cold. The colder it gets , the more they contract.
That contraction / making the interior dimensions smaller. Jacks the pressure WAY UP.
I imagine most long range hunters and shooters use temp stable powder and often magnum primers to get good ignition and lower SD.
Which can spell disaster when a load that produces full SAAMI spec pressures with normal ambient dimension s . Is fired in a much smaller chamber and barrel.
Anyway.
I just hope everyone is cautious.

 

[elkaholic]

That's a good point! I've always wondered when people report some powders have higher pressure in cold weather if it was always the powder or barrel contraction?

 

[Canhunter35]

I've havent seen pressure shooting at -40, but I've sure as heck noticed that even varget and h4350 will really drop off in velocity, some where's around 150fps

 

[KyCarl]

It's best to stay by the fire! Warmer days are coming. It was -5 last night and that's cold for here!

 

[Doublezranch]

In North Dakota, Long Range rigs stay in the house in the winter. We just finished a stretch of -55 to -60 with the wind chill. These temps aren't necessary out of the norm, but they only happen every few years. The other thing that happens is those long heavy barrels condensate and sweat like crazy. I'm not a real big fan of watching the condensation drip off a 400-500 barrel.

 

[the hunter]

So your brass case would contract to?

 

[hunter67wa]

lol you read my mind. went out and shot at 7 degrees the other morning to chrono my rifle and it was fine will shoot it at 80 this summer to check my powder sensitivity. No wind and sunny. Once temp hits 0 its no fun anymore.

 

[Ndfarmer]

Not saying it can't happen but I have coyote hunted with 223 and 6mm Ai in -30s and never seen anything. It wasn't best hunting, dogs lay low when it's that cold but it's better than not hunting haha

 

[ShtrRdy]

Copper and lead would contract too. Do standard chronograph even work properly at below zero temps? My magnetospeed doesn't work properly when the temps are teens to single digit.

 

[hunter67wa]

My magneto speed worked just fine at 7 degrees

 

[johnwm]

This is the best coyote hunting weather imaginable, IMHO. I find they are much more active during these temps; they are burning through calories simply not freezing, and they need food and lots of it. I was out several times over the past couple days during a local temperature of -40C (which is also -40F, it's where the two temp scales intersect). A couple hours at a time is all I can handle; I got a couple shots each morning, scored a few nice dogs. No problems observable, other than being dang cold! Windchill was right at -59C one of those mornings...that's about -74 American degrees.

Last winter I did some shooting in the extreme northern part of my province (Manitoba) at an actual temperature of -59C...thank goodness the wind was uncharacteristically still.

I honestly think you folks are just looking for an excuse to stay indoors. Your barrel has contracted due to the cold...so has your bullet, and everything else. Can anyone actually produce documentation of a problem caused by this?

 

[TGVet]

In North Dakota, Long Range rigs stay in the house in the winter. We just finished a stretch of -55 to -60 with the wind chill. These temps aren't necessary out of the norm, but they only happen every few years. The other thing that happens is those long heavy barrels condensate and sweat like crazy. I'm not a real big fan of watching the condensation drip off a 400-500 barrel.

North Dakotan's
Pray for global warming in winter.
Pray for global cooling in summer.

 

[Ndfarmer]

I seem to have best luck the day after a really cold streak. Johnwm do you have problems with crunchy snow when it's that cold and zero wind? It's almost like the sound travels for ever.

 

[tankgijohn72]

Good news! The brass, and copper will contract at a faster rate than the steel. Add clothes. Keep shooting. BTW. Good dedication at -40. My dedication drops around -10.

https://www.amesweb.info/Materials/Linear-Thermal-Expansion-Coefficient-Metals.aspx

This is the best coyote hunting weather imaginable, IMHO. I find they are much more active during these temps; they are burning through calories simply not freezing, and they need food and lots of it. I was out several times over the past couple days during a local temperature of -40C (which is also -40F, it's where the two temp scales intersect). A couple hours at a time is all I can handle; I got a couple shots each morning, scored a few nice dogs. No problems observable, other than being dang cold! Windchill was right at -59C one of those mornings...that's about -74 American degrees.

Last winter I did some shooting in the extreme northern part of my province (Manitoba) at an actual temperature of -59C...thank goodness the wind was uncharacteristically still.

I honestly think you folks are just looking for an excuse to stay indoors. Your barrel has contracted due to the cold...so has your bullet, and everything else. Can anyone actually produce documentation of a problem caused by this?