Caution in the cold

Cold Trigger Finger

Well-Known Member
Joined
Nov 2, 2012
Messages
978
Location
Copper Basin, Alaska
Well, I figured there were math equations that delt with this cold constriction.
However, I was referring to -40 ambient and colder. Not 30 below. There is quite a difference between -30°F and -40° F or C .
There always seems to be those that will push boundaries with things . Like long range shooting or being out in the cold ( just because most people say its too cold)
Blown primers, ruined brass and velocities of 400 fps more than normal were my instructors in this.
Once the firearm had warmed up, the velocities dropped steadily as the barrel warmed . Velocities dropped below normal above freezing temps by the last shot in the mag or cylinder( revolver) . Indicating the powder was still at or near the 40 below or colder temp.
I didn't figure it out on a chart , I did it with different firearms, a chronograph( that I kept warm by putting it in a box with heated towels under and along its sides.)
I Chronographed from my back porch using my woodshed with cords of firewood stacked in it as my bullet trap.

My experience is that in true cold temperatures ( -40 and colder ambient) .
Caution should be used when shooting.
Surely most people on here are familiar with using a torch to warm up froze on nuts , ratchet chain binders , threaded locker dog down systems ect.
Just a little heat from a small propane torch will make them expand enough to often times be unscrewed by hand. Instead of using a 3 foot cheater bar on a dog handle, binder or wrench.
 

Cold Trigger Finger

Well-Known Member
Joined
Nov 2, 2012
Messages
978
Location
Copper Basin, Alaska
The other point of this thread . Was the brittleness of steel in the cold. Combine higher than normal pressure with barrel steel that is much more brittle and its a recipe for unpleasant things happening very quickly.
 

RegionRat

Well-Known Member
Joined
Nov 11, 2012
Messages
60
Location
Redondo Beach, CA
Not that I would ever encourage people to go out in temps below -40 just to goof off, but it isn’t rare for guns and bbls to be used in very cold conditions. Think about those guns on aircraft up at altitude in winter weather...

The outside temps on many occasions went between -65 and -100 C and we didn’t have issues.

Yes, some materials have properties that include a very poor performance after an inflection point with temperatures within the range where humans may still operate. However, the steels commonly encountered for gun bbls are selected with many parameters in the trades. Arctic temperatures are part of the total picture in design requirements for military weapon systems and commercial technology will often follow.
 

RogerPA

Active Member
Joined
Aug 21, 2013
Messages
44
Location
Pennsylvania
.....Can anyone actually produce documentation of a problem caused by this?[/QUOTE]

Look up: “Low Temperature Embrittlement”. It has been covered before in other threads, here and elsewhere. I’ve learned more about it than I ever would have guessed...
 

shaughn

Well-Known Member
Joined
Oct 30, 2014
Messages
194
Location
manitoba
Oil and Gas has a fair few white papers about operating in Arctic cold and even among naval circles there are papers about how the various steels and metals react...and a lot of those papers were concerning Armour plate and big rifles...probably have to go digging in archives to find them..may be online, but like Janes.... I imagine you have to pay to view...Logging and open pit mining...
 

johnwm

Member
Joined
Apr 5, 2013
Messages
13
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.
Zero wind is so rare and so wonderful around here that I will never complain about it. :) Sound does indeed go on forever, but we never seem to have much crunch, at least not until later in the season. We never go above freezing, so there's never a thaw and re-freeze to create that crispy top layer. The snow just keeps it's beach-sand consistency through most of the winter; it's usually very quiet to move through.

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
Add clothes? I'm pretty sure I was wearing everything I own! :) Living up here you get accustomed to it; it's just winter. I had just finished sighting-in a new gun a day or so earlier and it needed to be blooded!

So if brass and copper contract faster, and from that chart it looks like lead will also, that should mean that pressures will drop if anything. Or are there other factors at play here?
 

tankgijohn72

Well-Known Member
Joined
Feb 11, 2014
Messages
257
Yes, pressure should go down based of the coefficient of thermal expansion. However, what the OP is seeing could be a change in burn rate due to something happening to the powder. Or the copper becoming harder and engraving forces increase. Otherwise, nothing would really explain the gross increase in pressure.
 

gator378

Well-Known Member
Joined
Apr 23, 2005
Messages
188
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.
I loved North Dakota when I was stationed up there. I sure had a good time
 

johnwm

Member
Joined
Apr 5, 2013
Messages
13
Yes, pressure should go down based of the coefficient of thermal expansion. However, what the OP is seeing could be a change in burn rate due to something happening to the powder. Or the copper becoming harder and engraving forces increase. Otherwise, nothing would really explain the gross increase in pressure.
Aaah! So more or less the opposite of what the old-time British gunmakers faced with cordite loads used in tropical climes...but with the same net result, i.e. spiking pressure.

Interesting about the engraving forces as well; I never would have thought of that.

It's like the old saying: I've read so much about the bad effects of smoking, drinking and over-eating...that I've decided to give up reading. :)
 

Latest Classifieds

Top