Hobbie,
That is correct. NEW Starline 44-40 is, well it's not really "straight" as it tapered a little. However, NEW Starline brass has no shoulder. Just a slight taper to the case. A nice easy trip thru the Dillon Expander/Beller/Powder drop die and presto, it's ready to seat a 45 bullet. I personally prefer a 452 for my rifles and pistols.
When fired, the strange looking round as first loaded, fills right out and becomes a straight walled 45 case. Since I start with new brass, I have yet to have a case split. I use anywhere from 160Gr bullets to 200Gr bullets, crimped firmly in the crimp groove and have NO Blow-By. I shoot an entire match and the Carrier Block/Mortice are as clean as a 44-40 rifle. At the end of a match I just chamber a fired round and run a couple of wet patches (PAM), a dry patch, an Oil patch and I'm done.