Problems with Lapua brass figured out

[Chinbullco]

A couple weeks ago I posted problems with "blue box Lapua brass" causing a buildup in dies that scratched case necks. The problem still exists and now its found its way to my Winchester brass. It is a scale from annealing. Tumbling in dry media or washing with or without STM cleans the scale and eliminates the problem.

The Blue Box Lapua brass is otherwise perfect. Some boxes of brass need cleaning others don't. Any brass that I've annealed needs cleaning before sizing.

 

[*MALICE*]

Scale? Really? I've never seen scale on brass from annealing. Strange.

 

[roberti11]

I found exactly the same thing, finally figured it out about a week ago after seeing the following video..

http://www.youtube.com/watch?feature=player_embedded&v=6a1G1XGhnTY

At the 2 minute mark they comment how oxides form on the brass after annealing, these oxides are very hard and can damage equipment used to form the brass. At that point in the video a light went on inside my head.

I also found that tumbling it stops the neck scratches, and looking back I noticed that this problem started when I started to anneal my Hornady brass.

 

[warrenb]

OP.

Thanks for posting the answer to your issues. I have never had this problem from annealing Lapua, win or remington brass but will likely clean after annealing now.

Interesting video.

Cheers!

 

[roberti11]

OP.

Thanks for posting the answer to your issues. I have never had this problem from annealing Lapua, win or remington brass but will likely clean after annealing now.

Interesting video.

Cheers!

I should have written a more comprehensive account, the first brass I ever annealed was Win 7mm WSM, I had no problem, next was Lapua 6.5-47, again no problem. I suspect that there is an issue with the brass composition, we know this varies with different manufacturers. Certain brass compositions seem to develop a very hard oxidation deposit after annealing, and others do not.

 

[Chinbullco]

Warrenb

OP.

Thanks for posting the answer to your issues. I have never had this problem from annealing Lapua, win or remington brass but will likely clean after annealing now.

Interesting video.

Cheers!

I guess that depends on your annealing process. I don't cool cases in water, they drop into a pan and air cool. Dropping annealed cases into water might have the same effect as tumbling or washing.