dirty necks?

[sigshepardo]

I'm beginning to notice the necks on my .30-06 cases getting dirtier the more I reload them. Is this due to resizing and trimming?

 

[PA-Joe]

Low powder charges will do this. Case is not expanding enough to make a complete seal. Its not an issue though.

 

[Doodlebugger45]

Sometimes it's the brand of powder you use. Sometimes it's the pressure you develop in the load. Nothing to do with sizing and trimming and nothing to worry about. I used to fret about it, even going to the trouble of spraying carb cleaner on them before tumbling. Now I just don't worry about it. Most of it comes off during tumblling. If not, I still don't worry about it.

 

[NESHOOTER]

Or a scotchbrite pad removes the residue quickly.....

 

[Ideal Tool]

Hello, sigshepardo. You mentioned "the more I reload them"..could be the brass is work hardening, and becoming stiffer & not sealing as it once did.
And yes, sizing will contribute to this.
You might want to anneal..but be careful..this has it's own pitfalls.