Ran across a .38 case today marked NT. I felt the primer fail to start on my 550 and removed the case to inspect it . It was marked NT, and appeared to have a crimp. I reamed the primer pocket with the same tool I use for .223 cases and thought I was good to go. Primer started in ok, but would not fully seat. I ended up pitching the case. Anyone run into these before? I have in .45 ACP, but nothing else.
