Temperature Question - Gunsmiths & Experts please

[shotgunner]

Which temperature does the steel in my gun become too brittle to fire from?
Would the temperature factor be different for say, a .22 lr vs. a .458 lott?

What would be the general low and high temperature extremes to fire guns in?

Would -75 F be too low of a temperature to safely fire a gun in?

Would somebody please elaborate on this subject for me?

Thanks!

 

[BobCat]

Depends on the composition and heat treatment of the particular steel in question. I do not know what steels are commonly used in firearms, but I suspect a lot of 4140; most stainless rifle barrels are 416R.

You can find some good articles by doing a google search on "ductile to brittle transition temperature" - with the quotation marks in place. More than you want to know, but a good start toward answering your question (giving it context).

There is another Metallurgist on this board, named Mete (I think) who may give you a better answer.

-75 F is asking a lot from a carbon or low-alloy steel.

Regards,
Andrew

 

[mete]

That's me ! Yes it depends on composition. The brittle transition temperature can be as high as 70 F ! It is one of the factors that that made the Titanic's hull brittle causing the sinking of that ship. Crucible Steel Co says their stainless barrel steel 416R is good for -40F and the 4140 should do better than that .But there are other components in the gun, firing pin, springs etc and for -75F I would like to test it .I suppose you could find people who have hunted in those temperatures but not me !! In WWII in Russia they saw those temperatures but I don't know the problems with materials. Lubricants are a big problem and often they remove all lubes and condensation is a major problem too.I think a well made gun should be ok to -40F anyway.

 

[Bear Gulch]

I would think that the temps at Stalingrad and then at Chosen Resevoir had to be close to that. Being outside in that temp becomes life threatening quickly. I would assume if I had to be outside and shoot in those conditions that the tensile strength of the steel might not be my first concern.

 

[BobCat]

A guy I used to work was a Combat Engineer in Korea. He told me stories about sledge hammer heads shattering from the cold, driving tent pegs into frozen ground.

Besides the properties of the steel at low temperatures, a lot depends on whether or not there are any small cracks that are already started. A small fatigue crack that might blunt and arrest at "normal" temperatures could easily "pop in" and run at cold temperatures.

This is a interesting topic and I hope it prompts any young people who read this thread, who are trying to decide between e.g. Electrical vs Mechanical Engineering, to consider Metallurgical Engineering (or Materials Science).

Regards,
Andrew