Primer carbon?

[mike a]

Shot a match today and had a dud. We’ll, I’m the dud. No powder. Pulled the bullet and thought you all might want to see how much Gunk the primer made. I fired 74 rounds today. I wonder if the powder burns that crap up.

 

[D Coots]

Did that yesterday...got to save powder whenever you can....Yep, it's messy.

 

[Rat Rifle]

I have heard it said that primer residue is a major contributor to barrel wear. Some shooters run a dry patch through anytime they get the chance to lessen the affect.