I have no idea. It was really bizarre because it was a ~1.5 inch wide ring that was about halfway up the side of the bowl. I also use corn cob media. I'm wondering if its from the polishing compound?? I do add a few drops of polish every time I tumble.
Funny you mention that, I cleaned my tumbler on Saturday for the first time in over a year. There was a thick black “ring” of crud bonded to the inside of the bowl. Had to scrape it off with a screwdriver 😂
I got my Acme bullets exactly one week after ordering. Eggleston bullets ordered on Monday are scheduled to be here tomorrow - though I think it will get delayed until Monday as they just left CA on Wednesday...
Yeah it looks like you didn’t have much of a crimp before. Ideally you’d want those bullets seated deeper to allow the casemouth to be crimped onto the cannelure. But I realize you have feeding issues so.