drying brass on top of wood stove, accidental heat treat

6.5 shooter said:
^^^^NOT^^^^ if the case was annealed into the web and case head area your screwed NO amount of annealing will bring the brass back. Brass is cheap, eyes and firearms are not
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THIS! Do NOT shoot this brass if you are not sure!!! If the whole case got too hot they WILL BLOW UP in spectacular fashion! Don’t ask me how I know this, please just take my word for it. Much less embarrassing that way!
 
"The grain structure of the brass begins to change - indicating the start of annealing - at just under 500 degrees Fahrenheit. At 600 degrees F, brass will anneal in one hour. At 800 degrees F, brass will take only a few seconds to anneal." This is taken from an article in MassReloading.
 
legi0n said:
"The grain structure of the brass begins to change - indicating the start of annealing - at just under 500 degrees Fahrenheit. At 600 degrees F, brass will anneal in one hour. At 800 degrees F, brass will take only a few seconds to anneal." This is taken from an article in MassReloading.
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Interesting.. that's the first time I've seen that information. Thanks!
 
I've done the same thing at least twice before, both with batches of .38spc cases. I was mighty pissed off with myself for forgetting them on the stove which absolutely reached temps of 500f , they were a beautiful multicolored tint like case hardening on a fine lever gun... I just tossed them.
I still dry brass on the stove constantly, but I try to be more attentive especially with precious bottleneck cases.
 
I put mine sitting upright in a SS serving line pan, then it goes into the electric oven (kitchen range) for 30 minutes at 170 Fahrenheit, which is as low as the oven will go. At the end of 30 minutes, I turn the oven off and leave the brass in it to cool.
I've been doing that for several years now, no problems yet.
 
I'm never in too much hurry. Wash brass when I get home and it can air dry a few days.

If I'm in any rush at all a pan in a sunny window or a colander over a heat register is plenty fast enough.
 
Chilly807 said:
Interesting.. that's the first time I've seen that information. Thanks!
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I wouldn't take that information at face value. Information posted in shooting media concerning the metallurgy of brass is so riddled with errors that it should never be presumed correct, unless you can corroborate it with other, more reliable sources.

I have a 1944 paper from a couple of scientists at Frankford Arsenal, the numbers in it are sometimes similar to the above, sometimes not.

"Residual Stress in Caliber 0.30 Cartridge Cases", H. Rosenthal and J. Mazia

"The production stress-relief heat treatment of 475°F for 45 minutes is capable of reducing the residual stress in the head of the caliber 0.30 cartridge case by almost 50%".

"An original circumferential neck stress of 30,000psi can be lowered to 15,000psi in 120 minutes at 400°F, in 30 minutes at 475°, and in 15 minutes at 500°"

"Murzda has shown that a 600°F treatment for 1/2 hour is sufficient to begin microscopically observable recrystallization in the head of the cartridge case."

My own experiments have shown that 800°F for five seconds will not produce any change to the grain structure of the brass that can be seen in an optical microscope, but that doesn't mean nothing has happened. People have the idea in their heads that "annealing" means recrystallization and reduced strength, and that is not necessarily true. The 475°F / 45 minute heat treatment mentioned above is an anneal, but it's a stress-relief anneal. It won't change the hardness much (if anything hardness will go up), it won't change the microstructure at all, yet it yields huge dividends in terms of keeping cases from cracking in storage, because it relieves the stress within the parts.
 
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BattleRife said:
I wouldn't take that information at face value. Information posted in shooting media concerning the metallurgy of brass is so riddled with errors that it should never be presumed correct, unless you can corroborate it with other, more reliable sources.

I have a 1944 paper from a couple of scientists at Frankford Arsenal, the numbers in it are sometimes similar to the above, sometimes not.

"Residual Stress in Caliber 0.30 Cartridge Cases", H. Rosenthal and J. Mazia

"The production stress-relief heat treatment of 475°F for 45 minutes is capable of reducing the residual stress in the head of the caliber 0.30 cartridge case by almost 50%".

"An original circumferential neck stress of 30,000psi can be lowered to 15,000psi in 120 minutes at 400°F, in 30 minutes at 475°, and in 15 minutes at 500°"

"Murzda has shown that a 600°F treatment for 1/2 hour is sufficient to begin microscopically observable recrystallization in the head of the cartridge case."

My own experiments have shown that 800°F for five seconds will not produce any change to the grain structure of the brass that can be seen in an optical microscope, but that doesn't mean nothing has happened. People have the idea in their heads that "annealing" means recrystallization and reduced strength, and that is not necessarily true. The 475°F / 45 minute heat treatment mentioned above is an anneal, but it's a stress-relief anneal. It won't change the hardness much (if anything hardness will go up), it won't change the microstructure at all, yet it yields huge dividends in terms of keeping cases from cracking in storage, because it relieves the stress within the parts.
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that is indeed the case given that the verb "anneal" can mean different things in engineering being related to the end-goal.
for the purpose of this thread the bolded part indicates that the OP is safe to use his brass.
especially since it is not the case that holds the firing pressure but rather the chamber+bolt is
worst that can happen upon firing a soft case is that the primer pocket is enlarged so that it won't hold a primer any more.
 
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