I was setting up my brand new Dillon RL-550B this week-end and started working through my backlog of .45 ACP empty cases. My empty brass is a mix of my own prior re-loads (mixed manufacturers) and range pick-ups. I found about a half dozen .45 ACP cases with small sized primers. They were marked "WIN NT". I culled and discarded the rest of them. I had heard of small primer .45 ACP, but had never see them before. What is the intended purpose/benefit of this case variation?