Exposing brass to high temperatures - any negative side effects?

[FromSA]

Hallo everyone,

I was hoping someone who knows more about metals (in particular brass) could help me out. Generally I use very little lube when sizing brass. Despite using so little I dip my brass in benzine/surgical alcohol every few loads to clean away the lube. Once I've cleaned off the lube I put the brass through a bit of hot water. Now here's my question - if I were to dry the brass in an oven at say 200 degrees celsius, would it have any negative effect on the brass? I normally pre-heat the oven and then leave the brass in for 4 minutes (sounds more like baking than reloading, doesn't it?). At present I'm using Lapua brass.

Thanks

 

[Mikecr]

Grain structure of brass doesn't change until 450deg.
So no, drying cases in the oven at ~200deg won't hurt anything.

 

[westcliffe01]

Mike, take note he said 200C not F.... No need to go that hot. The base of the cartridge derives its strength from work hardening. If you get the base too hot, you could have a failure near the face of the bolt where it is not 100% supported. With any rifle cartridge, that could have consequences for your firearm, your left hand and possibly your face/eyes from the hot gases escaping from the action.h

You should have a warming drawer so use that, or else set the oven on its lowest temp. All the water will evaporate at 60-70 and it will still be so hot you couldn't touch it without pain.

If you size without lube it will not be long before the die starts galling and it will rapidly get worse. Given the price of brass today, that is a bad idea.

I wash my brass after resizing using a tumbling drum and stainless steel pin media and detergent (same stuff you use for the dishes).

You can read about that here Stainless Steel Reloading Supplies | Tumblers, Separators, Media, Brass & More!
For washing after sizing I only run them with warm detergent for about 20 min. The hour long tumbling is only needed for heavily tarnished range pickup brass like they use in their advertising.