Home Forums Reloading Big Game Rifles Is this bad - brass discolored after oven drying.

I tumbled 140 30-06 cases with a bit of citric acid (not a lot at all), some Dawn dish liquid and the saved liquid I previously used that had whatever Frankford Arsenal gave as a free sample when I bought the tumbler. They came out after two hours looking pretty good. I rinsed them briefly and dumped them onto a towel to remove most of the water. Then I put them into the toaster oven for one hour at 275*. They came out with a dark, iridescent blue/purple color to them. Other than looking odd when loaded with a bright brass bullet, they look kinda cool. However, I'd like some reassurance that I didn't harm them in any way that makes them unsafe. What thinks you?

My pictures were too big to upload, but I'll get to work on that and try to get them posted here for reference.

I think 275 is too hot. Try 130-160 degrees next time.

Thanks, Dinny

The ones on the top of the pile were discolored the most while those more covered underneath the pile were less affected.

But did I harm them? I can deal with the color, and yes, I'll go a lot lower next time. Thanks.

They look…annealed?

My same thought. As far as damage, I don't know for certain but there's gotta be a reason why serious reloaders only anneal the shoulder/neck portion of the case.

Check out these cartridges loaded in Lapua brass. Note the color in the neck/shoulder area. That's the only place you want to see that color.

275F isn’t going to hurt anything.

Retumble. Use less Citric. Rinse thoroughly immediately after tumbling. Air dry.

The problem is the cycling of the toaster oven and proximity of the heating element may have exposed some of the cases to a good bit more than 275.

To what? 350F? 400?

Still isn’t hurting anything other than accelerating surface oxidation due to residual citric acid.

You have to get up around 700* to anneal brass, They're just tarnished.

^^^ Actually you only need to get to the high 400Fs (482F ish) to start annealing rifle brass, but would need to be there for a long time to do enough damage to the case head (ie reduce strength).

Example below of a brass alloy (copper/silver). Caution: this is not be same composition of your brass (copper/zinc). for illustration purposes - but get the point

They may have just needed more rinsing. Also don’t let the brass sit in a wet tumbler for long after a tumbling cycle. The contaminates will drop out of suspension and coat the brass. If you ran it in a timer and it finished 20 minutes ago run it again for a few minutes then rinse it right away. The reason it’s helpful to use a squirt of Dawn or wash and wax car wash is to hold the junk in suspension better.

After a cycle I dump the liquid out then fill it back up with the hose and rinse it a few times. Then I drop the brass in a bucket with a gallon of distilled water and swish it around, then I dry it. I reuse the distilled water.

I would be hesitant to use a toaster oven to dry brass. I use an old food dehydrator. It holds a lot of brass and dries it well without overheating it or having any hot spots around a heating element. They are cheap at places like Goodwill.

I know that the cleaning solution that comes with it can be reused but I wouldn’t add any more citric acid as it may already be acidic and you don’t want to overdo it and leach too much copper out of the brass.

I thought I had messed up some cases after tumbling once but I retumbled them for 30 minutes with just a squirt of Dawn and they came out great. They just had a film to them. You might try that, then rinse it real good and dry it again at a lower temp and see how it turns out.

I'd keep a close watch on them when I shot them.

Yep, from top to bottom........

Here’s a general question - What does annealed look like?

What your “seeing” in the above Lapua cases is oxidation caused by the annealing process. You can’t see annealing unless you look at the grain structure under a microscope. I.e. Brass would look the same if you could somehow heat the necks only to 300F for a longer period of time - but there would be no annealing at that temp.

My Lapua cases have never looked like that....I guess I got ripped off.

I put mine in the Sun on a cookie sheet when it’s hot, oven on lowest setting for 30 minutes if sun isn’t out.

This is what I thought too. I was pretty sure that the temp was not harmful otherwise I wouldn't have set it there. Ordinarily, I dry things as 150* so I guess I was just a little impatient that night.

Did you preheat the toaster over before placing the brass in to dry? If not you just may have ruined that brass. Just placing them into the oven cold without the preheat means the oven has to reach the preheat temperature before "cooking" whatever was placed in the oven. To do that it get way hotter that the set temp for a while, just hot much hotter I don't know. However, an example. I use a toaster over to oven treat cast bullets. IO put a bunch of carefully cast bullets on the tray and placed then into the oven, turned it on and then set the temp. After letting the bullets bake at the proper temp for the four hours, I pulled the tray from the oven and there were the 200 bullets. All had slumped and were useless That temp had to have gone over 550 degrees as the oven preheated itself and was high enough to ruin the bullets.

What you might try as a test is if you have some "good" brass on hand and a fine file, run the file across the rim of the "good" cartridge lightly and note the amount of drag. The try one of the tarnished cases. If the drag is greater, there's a good chance the brass is ruined. I can't think of any other way to test them and shooting them without some kind of test is a gamble I wouldn't take. your choice.
Paul B.