joeb: I have used Unique with cast bullets and have had ringing problems in chambers where shorter brass is used. This has happenend only in one of my 44 magnums when I used Unique under a cast slug out of a 44 spl case. Hasn't happened with that powder in38/357s though. Unique is a fairly fast burning powder and if you use it with a 45-70 case in a 45-90 chamber under a soft cast bullet you may get the lead ring buildup. I think that's why the bp shooters advocate for the use of a wad between the powder and bullet, to keep the bullet from becoming molten on the bottom and leaving lead ring buildup in the chamber. I sure HTH. Mikey.
