Lyman single stage press difficulties.

[ted_dent]

I also tumble a little after sizing and do not understand how media can be contaminated. Isn't it already "contaminated" with burnt/unburned powder, primer residue, dirt, sand and dust?

Yes, but it's not contaminated with oil, which most case lubes are. Unlike other residues like powder or primer leftovers which are dry, oil is not and doesn't appreciably dry up. Therefore when you tumble your sized cases in lube contaminated media you are providing a medium that will allow dust, dirt and any other crud in the tumbler to stick to the cases, which doesn't do your chamber any favours when you load rounds in the gun.

I'm a bit anal about cleaning my brass. Normally I tumble it in Lyman green media to do an initial cleaning, then size & rinse in solvent to remove the lube and finally I tumble it again in fine corn cob with polish like jewellers rouge or Flitz brass polish. Looks better than new and the cases are as slick as snake snot. It's probably overkill but I figure if I can't be the best shooter on the line I'm going to have the best looking reloads.

My media also lasts a lot longer before I have to replace it.

 

[TargetAcquired]

I started with q-tipping, but it's cumbersome and annoying, so I just built a very simple felt jig on a screw that I can attach to my bench. I lightly lube the jig every 10th case or so, and just push the case mouth onto it - don't even have to touch/hold it. just as effective as a q-tip, only 100x more efficient.