22LR prep before deriming.

[anotherred]

I'm looking for more ideas how to prep the brass before running them through the derim die. Ultrasonic? Stainless tumble? Soaking in a magical solution to break down the powder residue? Quick shake to remove sand and have at it?

[tiger762]

Wet tumble with stainless media, for two reasons:

1. To remove not just residue but the fine glass dust that was in the primer mixture. Glass dust makes the ignition process more reliable but will wreak havoc on the derimming punch. I have 12000+ rounds on mine (RCECO), but can tell a slight discoloration even with wet tumbling the brass religiously.
2. To deactivate any leftover primer mixture. I have had a few in the oven "POP", making a mess as they toss around the empties around them.

Do not anneal before derimming, lest you'll have one out of three stick to the derimming punch due to lack of brass springback. Clean, then derim, then anneal, then carry on with the rest of the process, optionally doing another cleaning.

[runfiverun]

that's pretty much my routine too.
I do an additional pin cleaning after annealing to get all that gunk off the jacket.

[anotherred]

The few hundred I've made so far, I used the ultra sonic on the fired brass, derim, wash, anneal, stainless tumble. I wasn't sure if the stainless pins would get the primer gunk out. I'll give that a try tomorrow, now I have to see if I've got 2# of sorted brass.

[anotherred]

Got them tumbled, and I have to agree, this is the best way yet! Thanks.

[runfiverun]

I don't think the pins themselves get the gunk out.
the washing action and tumbling, plus anything the pins can do inside the case is what gets the compound out.

[anotherred]

I wasn't thinking the pins would do as good a job as they did, hence the reason I was using ultrasonic.

[Prospector Howard]

If you think about this for a minute you'll realize that the pins aren't going to get the grit out from between the rim very good. The space between the rim is only a few thousandths of an inch wide. No stainless steel pin is small enough to get in there. The only way I've found to get the most possible grit out from between the rim is vibrating it out with the ultrasonic cleaner. I've tumbled the heck out of brass and then put them in the ultrasonic cleaner, and the amount of grit that still comes out is amazing. It's impossible to get it all out, but I can get most of it by soaking them in a water and citric acid bath for a few days first, then tumbling them, and finishing off in the ultrasonic cleaner.

[tiger762]

That's true about the space inside the rim, but I think the theory is that at ignition, that glass dust got mostly blown out along with primer residue, and the pins are scrubbing the inside of the case wall. Maybe they're only getting 99% of the glass dust. Better than nothing.