Has any one seen yellow residue on the inside of a case after a bullet is pulled? Looks like sulfur, however I pulled 10 cases and 4 out of the 10 there was yellow residue and some of the flakes were yellow.

Not sure what to think.

Thanks

BTW, welcome to the forum! 
Yes I have seen it on several pull downs...during the investigation as to what it is, we surmise dampness reacted with the powder and brass...

In this picture of some misfired rounds the primer compound was mixed into the powder.




This was in Ted Nugent Ammo.


Littlestone Ammo Blue Dot.

Thanks for the welcome.  I was glad to find this place.

Mine rounds looked like a couple of your pictures... I guess my question is why it happened. My power in the hopper is fine, I check the weight on each round and the powder looked like it should.. Humidity is considered low.  The only thing I can think of is my work lamp??? I did notice that when I was cleaning up my power meter there was some moisture.. great... now out of the 300 rounds I made I worry about them.... and figure out why some have it and others do not....

Thanks again for your help.

It is possible that the primers were not totally dried in their process, and moisture could come from them.

However, I fear that this mostly comes from wetness inside the casings, when powder comes in contact it could react with the nitric acids of the powder.

When I first saw this in the Ted Nugent round I pulled-down, I thought it was and additive of some kind.  But as you can see from the pictures some reactions have coated the entire charges of powder.

hmm... cases where new - had them for 6+ months... They were stored in their box from starline... not sure about the primers... I did purchase a new box recently but only used half along with my previous purchased ones... that would make sense while only some had that... Maybe I should pull of couple of more from my other lots.

Thanks for the info.... The cases with the yellow, deprime and give them a cleaning?

That's the color of the powder itself. The shiny black color only comes from it being coated with graphite to make it flow for volumetric loading. If the graphite rubs off and adheres to the case, or the powder doesn't burn completely, you see the yellow to greenish powder. Nitrocellulose is actually white or transparent, it's the various additives that give the color.

Thanks. So the powder on the side walls and some of the flakes turning yellow could be natural?

I primarily use Titegroup and have noticed this also. I use Winchester, CCI, and Federal primers. If memory serves, the Winchesters didn't do it. I also use HS6 but for 10mm and don't load as many of them. Seems to be worse the more strokes it takes to dislodge the bullet.

Thanks Snuffy.

I was using a kinetic puller, when I did pull using my RCBS collet puller I did not see this... I used the kinetic puller as the RCBS indented the bullet that was pulled...
The taper crimp is only just enough to take out the flare as there are no marks on the lower part of the bullet. The RCBS works just fine on my 45 auto bullets without any marks...

Thanks again.