I wet tumble my cases "BUT" it can pound the case mouth and it is made worse the longer you wet tumble.

The fix for this is to trim and deburr your wet tumbled cases each time you tumble. I started wet tumbling after my sons talked dad into getting firearms that throw perfectly good brass away and makes you go look for it. Meaning I got tired of my AR15 cases scratching my dies and cases. These cases that were bouncing on the ground can pickup dirt and grit that can get embedded in the sizing die. And wet tumbling scrubs the cases clean of any embedded dirt and grit that scratches your cases.

And there is a second problem with wet tumbled cases when the case mouth becomes peened and not trimmed and deburred. On many resizing dies there can be a rough edge at the neck shoulder junction left over after factory polishing. This area of the die will pick up brass from the peened case mouth and soon you will have brass rubbing on brass and scratched necks. And brass can also build up on the bushing in bushing sizing dies or titantium nitride (TiN) coated pistol dies which is strange.

Below in several forums many reloaders were complaining about scratched necks. And the die will need to be polished to remove the brass from the neck shoulder junction of the die.

This happened to me and I used a snug fitting shotgun cleaning mop chucked in a drill and used J&B Bore Paste, automotive rubbing compound, etc applied to the mop to polish the die.