Brass cleaning question

[Stewart2550]

I have some 300 PRC brass that I threw in the tumbler to clean up. I am using a Frankford arsenal Quik-N-EZ tumbler with crushed Walnut media. I also threw in some 22-250 and 270 brass with it. The 22-250 and 270 brass came out clean and 300 PRC brass came covered in gunk. I pulled it out and cleaned it off and threw it back into the same media and it came out clean. Curious to what is causing this and how do I avoid it without changing up my setup. Pictures are after the 1st tumble and after they were cleaned and thrown back in.

 

[Carlos88]

Did the brass have any oil residue on it?

 

[bert2368]

What, if any polishing compound are you using?

(BTW: I quit using dry tumbling a long time ago, first going to ultrasonic, finally to wet tumbling in water/Dawn/Lemishine with stainless steel pin media).

 

[Stewart2550]

Lyman Turbo Charger.

 

[Stewart2550]

Did the brass have any oil residue on it?

I'm wondering if it did. I did 7MM Rem mag brass with the same issue. This was not mine and my first time prepping it so I didn't think about that.

 

[bert2368]

What are you using for case lube during sizing?

 

[Stewart2550]

Unique case lube, but those cases are fired and deprimed not resized.

 

[bert2368]

Were the cases that gunked up resized/lubed with Unique the last time they were loaded.

Do you clean the case lube off after resizing, or leave it?

 

[Stewart2550]

My guess is they were not cleaned after resizing as my dad was the last one to load them. He reloaded for me before I started to do my own. This leads me to believe that case lube is probably my issue as my other brass has never had this issue. I always clean my brass after resizing and have never had the issue. He uses Hornady One Shot and I don't think he ever cleans it off.

 

[bert2368]

A reasobable guess, easy enough to test if you want to confirm.