Residue on casing after firing

[Darksith]

I am finding that after I shoot my reloads that on the neck on my casing there is black gunk...the best way to describe it. I am guessing that its just gunpowder residue. Is this normal?

[Lavid2002]

Normal, just clean off with steel wool or tumble them before the next reloads.

[Magnum Wheel Man]

1st, as already mentioned powder residue on the cases is not unusual... often on lighter loads, you'll see this, partially because the case doesn't expand enough to fully seal against the chamber walls, & allows the expanding gasses to force its way partially back into the chamber... you did not mention the cartridge, but this can happen with both bottlenecked & straight wall cases...or in using some particular powders ( Unique, for example ) they are just dirtier powders... I like to use Unique in my Montados in 45 Colt, as they "almost" look like black powder with the smoke & soot, but lack corrosion & fouling issues of black... also some powders will do this if you don't have enough crimp to get the case to build up enough pressure to seal off the chamber, or get good ignition of the powder...

[SL1]

Some cases have a tar-like sealant put in the neck by the factory. Others have powder residue that is inside the case, paritcularly down in the bottom around the web area, that is hard to clean out.

I use mineral spirits for both. Tumbling takes a LOOOOOOONG time to remove this residue if I don't use mineral spirits first. But, tumbling cleans-up the cases nicely after I get the gunk off with the mineral spirits. I am still looking for an easy way to use the mineral spirits. I can soak, but wiping is still necessary and a pain in the [back end].

On the other hand, powder residue on the OUTSIDE Of the case neck seems to come right off when I tumble in anything.

SL1

[chris in va]

I find a straight blowback gun like my HiPoint carbine will severely foul the casings a lot more than a locked breech design.

[bigalshootmupper]

I also found powder residue on the case necks of my reloads for my 6mm Rem. I am loading about 4% from max load and I still get powder around the necks. I can wipe it off with my fingers as it isn't burnt on there. I am thinking it might be the Remington brass that I am using, maybe it is too hard and doesn't expand enough. My other relaods using Federal brass for my 308 never showed this. But no problems with it though as I still can shoot under 1MOA with my hunting load.

[ZeSpectre]

Normal for the reasons others have stated. What powder are you using?

I get that BAD with some of the lighter loads of Unique but if I bump my loads up just a hair the issue goes away (the brass seals better on the chamber).

[Unclenick]

Except for very low pressure loads, a bullet doesn't slip out of the case straight out, but rather the pressure opens the case up by expanding it from behind the bullet and forward along its sides. The very end of the case stops expanding as soon as gas starts to bleed past the bullet, which is before the last fraction of an inch of the mouth has expanded. That's because the gas gets free to go around the end of the mouth and equalize pressure on both sides. The result is, you see a slight inward curve of the brass at the case mouth, even if there was no crimp. That small radius often has some fouling on it even if the rest of the case sealed well against the chamber and is clean.

Carbon hardens over time, so the faster you use a solvent on a case after shooting, the easier it is to get the stuff off. Mineral spirits gradually makes the oily fouling sludge-like, so it comes off in a tumbler. A faster solution is a dip in Ed's Red, which is cheap to make (you can download a PDF file with the recipe from my file repository). You don't need to soak it. Just dip the cases and let them sit in a basket until the excess drips off. I know a fellow who keeps a jar of Ed's Red with him at the range, and when he polices his brass he uses a cotton swab to moisten the inside of his case necks with it immediately. That lets them clean up completely at the neck to promote uniform neck tension.