What do you use to polish the inside of a resizing die?

Noticed from my last batch of reloading .45-70's (about 40K through the dies so far which are the Redding Competition Pro series - heat treated steel), that there were some minor "scratches" on the outside of the cases.

I figured that since I normally tumble these cases in a 1/2 lizard litter (crushed walnut) and 1/2 corn cob media, it was likely the dust from the walnut part of the media that may have still adhered to the brass while reloading over the years - even though in micro quantities.

Purely a cosmetic issue (I'm thinking) since I've never had a visible (or audible) problem with case integrity, whether with "God of Thunder" or "For Plinking Only" loads.

And when I can visibly identify residual dust on the cases, I either blow off the cases with a leaf blower (it counts as exercise chasing them around the yard), change out my tumbling media, clean the tumblers completely, and/or tumble 10 or more (snipped down to 40 individual but narrower sheets) dry cleaner fabric softener sheets to pick up the loose particulate.

At some level, all of these solutions "seem" to work whether individually applied or as a hefty dose of multiple solutions.

Despite cleaning out the inside of all the .45-70 dies using multiple patches lightly "scented" with 90% rubbing alcohol every 1,500 reloaded rounds or so (which also removes minor amounts of stuck "lube" residue from the seating and crimping die), the scoring that occurs on some cases tells me I'm not getting to the root of the problem - which may be scored dies from the micro walnut dust.

Or maybe my die cleaning regimen is working these days and the visible case scoring occurred years ago during my lazy/deferred cleaning days and I'm still reloading these cases which never had issues except this cosmetic one?

Most of the cases are WIN, BLACK HILLS, REM, and STARLINE.

I'm thinking of polishing the inside of the dies, but instead of using 1000 grit sandpaper, maybe Flitz, Simichrome, or jewelers rouge. And either using a bore mop (not a bristle brush) affixed to a drill and saturated in one of the polishes and spinning things around for a few minutes on each die.

Any thoughts how to successfully address this niggling dilemma without destroying the dies? :o

I would first clean the die. Take it apart, put it in an ultrasonic cleaner and let it go for about 10 min to make sure any/all crud that might have accumulated is gone. If no ultrasonic, take it apart and put all the parts in a lidded container, cover with acetone and shake it up. Then take it out and with a good light see if you can see any problems. If can't see anything, then run you finger in the die and see if you feel anything. If nothing, run a case into the die and see how it comes out. If still has scratches then I'd use emery cloth (1000/1200/1500 grit) wrapped around a wooden dowel and run that in and out of the die a little to see if that helps.

Only die I ever had to polish was a 50 Beowulf die. Some Flitz and some buffing tips for the dremel on low speed. Fixed my woes.

I have several Lee dies I use. They tend to be not as "smooth" as some of the higher end dies though. What I have done with mine is to take them apart, clean them, and find an appropriate bore mop size (small shotgun ones) and use Flitz and a cordless drill for a minute or two, give them a good cleaning afterwards. The before and after using a borelight looking at the walls of the die shows a big difference.

Smooths them out a bit and they cycle cases much nicer. That is the method I have been using with no issues.
Attachment 109119

These are the bore mop type I use, finding the right size for the inside of the die is the hard part.

Start with the absolute least aggressive polish you can find. And work your way up.

Or buy a new set for $140 on sale right now at Brownell's

Flitz or JB bore paste on a mop in the drill.

As stated above use a snug fitting bore mop and J&B Bore paste, Flitz, auto motive rubbing or polishing compound, Mothers Mag and Wheel polish, etc.

I have even taken the die apart and put the body of the die in a vibratory tumbler and let it tumble all night using treated walnut media.

The above method will also remove any rust or corrosion from the body of the die.

Resizing dies are heat treated and extremely hard and polishing the die will not harm the die.

I started using a wet tumbler with stainless steel media after getting semi-autos and the brass landing on the ground and picking up dirt and grit.

Switching to wet tumbling that would scrub the brass free of dirt and grit with far less chance of scratching the brass or becoming embedded in the die.

The flitz semichrome or jb are good, but for cleaning size lube and bullet lube nothing is better than number 9. Melts that stuff right out.

Many thanks for everyone who posted here and offered solutions - I'm very grateful that you took the time to suggest a fix for my problem.

I'm gonna start with the least invasive of these solutions when I get pack from the PAFOA shoot up in Jersey Shore this weekend.

I promise to circle back and let you know what worked for me...

You guyz are the best! :)