Did i just muck up a load of brass?

[Niscola]

Ok so i deprimed and washed about 100 cases. Then I put them in the oven to dry since it was already on at 400. They spent about 30 minutes in the oven.

some of them are a little darker, some have taken on a reddish tinge. i would think that 400 is a little low to have annealed them. but i want to make sure before loading and shooting these

should i just toss these or will a good scrub with steel wool suffice?

 

[downwithdion]

 

[.Ben]

that was a bad idea!!!!!!!!!! i dont kno if 400 is hot enough to have anealled them if it did the case heads could be dangerously weakened....someone else with more experience will chime in i am sure....

what caliber brass is it????....

 

[Niscola]

7mm rem mag once fired

 

[acrashb]

some of them are a little darker, some have taken on a reddish tinge.

I would think that a colour change was a good indicator of something happening to the metal.

 

[denydart]

http://www.6mmbr.com/annealing.html

Just re-read a portion in here and it mentions 495 F as the "magic" number but how sure are you that your oven thermostat is set properly? I don't like the sound of colours changing although blue is the classic annealed colour.

 

[Finger Toes]

I would NOT! use that brass. Never use an oven to dry or anneal brass. One piece that is heated beyond critical temp will soften the critical areas and can do nasty things to your face.

 

[BattleRife]

Something doesn't add up. I have annealed brass at 400 Celsius (only for a few seconds, mind you) and it doesn't show a colour change. Are you sure there wasn't some old french fry grease or something in there that may have stained the cases?

 

[CyaN1de]

Brass which has been "work hardened" (sometimes referred to as "cold worked") is unaffected by temperatures (Fahrenheit) up to 482 degrees (F) regardless of the time it is left at this temperature. At about 495 degrees (F) some changes in grain structure begins to occur, although the brass remains about as hard as before--it would take a laboratory analysis to see the changes that take place at this temperature.

The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.

If cases are heated to about 600 degrees (F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined. (For a temperature comparison, pure lead melts at 621.3 degrees F).

The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees (F) for some 15 minutes.

 

[corney]

I'm curious about the washing part?

I'm relatively new at a this also. Why did you have to dry them in the oven?

Help me get this.

thanks

 

[John Y Cannuck]

Problems like that are why vibratory case cleaners are a good investment.

Me, I don't worry about annealing brass. When it's done, it's trashed, period.

 

[Niscola]

 

[juanvaldez]

I'd bet they are fine, the reddish tinge could just be the residue from whatever you cleaned with. I've seen it before on cases I oven dried and they were fine. 400 is a little hot though. I'd keep it around 150. I once let some boil dry by accident and they were fine even after sitting in red hot pot for a few minutes.

EDIT - after seeing your pics, I'd toss em


Cheers

 

[joe-nwt]

7mag brass is cheap and common. I would go buy some more. Not worth the risk.

 

[B]

Chuck it, if the casing fails it could have DRAMATIC consequences.

 

[Buck45]

Thirty dollars for brass, $1000 for rifle and scope...FACE PRICELESS.

Chuck them....

 

[Niscola]

the colour changes a lot with the angle and intensity of light. this was pretty much a worse case scenario with no flash

i'm not arguing. i just wanted to clarify. with normal room lighting most just look dull

 

[bluebell]

I have never washed brass. Once fired brass would not even need tumbling. After a number of loadings, cleaning by tumbling is the way to go.

In this case I would not take a chance and agree with several of the posts upthread. In the interests of safety - discard the brass.

 

[anchor3593]

Heat one up with a torch and cool it, then push the side of the neck against a hard corner - like a tool box. You will immediately notice how soft it is. Now try one of your Betty Crocker cases and see if it is anywhere near as soft.

Baking extremely clean cases may discolour them before softening.

Okay - So I just went to the workshop and experimented with cases.

The discolouration such as yours show, happens early on in the heating process and I was able to duplicate it before annealing temperatures were reached.

When annealling a neck in air - with no pan of water, the case head turned that colour.

When annealing normally, one would likely pass that temp without even noticing it.

I remember some old ( military?) brass that was discoloured like that ( 6.5 -55 maybe?) part way down the cases.

If the necks are mushy soft, thats too bad, but if not, I would load up a handfull and watch for loosening primers.

And remember - Everything that you read on the internet is true - experts check it all daily to guarantee verity.

 

[Johnn Peterson]

Scrap them and chalk it up to a lesson learned. Better to be safe than sorry. At the range in the burn pit I've seen brass that same colour. Junk'em.