50/70 bullets

[Kurt]

Most of the time you won even notice the paper rings until you have a cartridge that is tough to seat and then it might get passed off as powder fouling.
Paper rings as well as lead rings are there. Lead rings you can more or less control better from not happening using a GG bullet as well as cutting down lead smears from starting at the 45 degree chamber end that get smeared up into the throat if you place the lube groove of the bullet partially ahead of the case mouth then the void between the case mouth gets filled with lube as the bullet moves forward. I found this greatly reduces the lead smeared throat. But then again if you have a hard bullet with a poor wad base and slightly undersized bullet is seated off the lands then the gas cuts will do the dirty work.
I have a lot of hard recovered bullets in my box that look like nice have been nibbling at the base.
That 45 degree transition at the end of the chamber is good for smokeless powder and jacketed bullets but not for lead bullets, PP or GG.
The .22 rimfire is the only chamber that has not changed over time and those chamber ends range from 1 degree to 3 degrees.

Kurt