Lead ?

[SgtDog0311]

I took it out today to test something (warning - smokeless load for now)

When I shot it last (.376 bullet in a .376 groove diameter barrel) with a Walter's Wad at the base I got these lead rings. Time before that same loading but no rings. I suspected they might be because I'd left the bell on the case neck. I had done that because they chambered fine and I thought maybe they'd help center the full-lenght-sized cases in the chamber better that way.
   

Something in the bell remaining encouraged the rings because today I didn't get but two rings (in all three sessions there is no leading in the bore). This time I layed the bell back down with my sizer.

Accuracy was good (at 50yds) insofar as I am with iron sights. First flyer high and left was the first round from a freshly cleaned barrel.
   

Appreciate the observations - don't want to do anything to the chamber that would degrade it as a BP rifle and I have not dug that far into Black Powder yet... but wanted to get some answers before taking to a couple shooting events this summer.