Do you guys trim and chamfer your rounds before you tumble them or after?

I chamfer new brass and shoot them till they split the neck and never tumble.

Tumbling is the first and final step I do. When trimming, chamfering, and deburring; you will still get brass shavings where you don't want them. A final tumbling will get rid of the brass shavings and your case lube.

I tumble after I shoot them, before I resize them. Trim and chamfer them after sizing. I only trim when they get to max length. I've never had a problem with brass shavings, and case lube will not effect the round. I wipe the outside when I pull it out of the die anyways. The little lube that is on the inside of the neck gets wiped off by the die.

Failure to properly remove sizing lube can cause erratic chamber pressures in a match chamber.

Lube on the case body will attract foreign debris you don't want in your chamber.

It isn't catastrophic. But removing it is easy insurance.

Yeah but your not supposed to put it on thick either. I use the pad and lightly roll the cases across it, it leaves just enough lube on the cases so it doesn't stick. But I also wipe them down after sizing anyway.

After firing I tumble my brass so I'm not running a dirty shell through my dies. Grime will scratch the inside of the die. Then I clean them with alcohol to remove lube, blow dry with air, check length, trim and chamfer if necessary, blow out with air again, then prime and load.

That's how I do it.

Jay