Re: tumbling media in bulk ??
"i will go buy that nu finnish tomorrow, i bet that wax would possibly seal around the primer and around the neck as well.. ya think ?"
Occasionally.
Nu-Finish isn't a <span style="text-decoration: underline">wax</span> at all, it's an auto polish that works on paint and soft metals, same as many other polishes.
Most people keep adding polish when they don't need to. It turns the media black and the excess dry polish makes a lot of dust. All that's normally needed to "rejuvinate" polish is to add a couple ounces of mineral spirits, aka "oderless paint thinner", to the tumbler and let it run a few minutes before adding cases. The thinner loosens/softens the crusty polish and lets it keep working for a long time.
Personally, I don't care for a phony looking glittery shine on my cases. I add a few spoonsful of diatomaceous earth (the same cleaning powder that's used in toothpaste) to new media and my cases have a soft matt finish look exactly like factory new stuff after I tumble.
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EDIT NOTE: I fully agree with Mr. Dtarget (below) that the 20/40 grit is the only way to go. It's much too fine to plug flash holes but works just as well as the larger sizes.