Short answer is yes, you can reload steel cases, but why?
Unfortunately this thread shows the general lack of basic knowledge of the subject exhibited by so many that do not hesitate to post on a subject they know nothing about! Let's look at what really is the situation!
1) Steel cases are made of quite soft steel. They are easily sized but lose their ductility in one or two loads and spring back so they will not hold a bullet.
2) WWII EC and ECS .45 cases used standard .210 primers. The early F.A. primer that was .204 was not loaded after sometime in the 1920s as I recall. Regardless EC & ECS cases can be loaded with standard LP primers.
3) Most steel cases are Berdan primed. True, they are European so that wold be expected. Same for European manufacture brass cases.
4) Can't get "pistol size" Berdan primers? BS! All you need to do is find a distributor which stocks the correct size. They aren't S, L, SR, etc, Berdan primers are sized by diameter in millimeters with no regard to whether they are to be used in rifle or pistol ammunition, usually. Old Western Scrounger used to be a source.
5) Will wear dies. Just lube them a bit heavier than brass.
6) Is there a good reason to load steel? Absolutely not. Likewise any Berdan primed cases. While either can be done there is no good reason to do so, but let's not fabricate baloney excuses as to why it cannot or should not be done like many have done.
RWSmith makes some good points, but it is not likely you will break a carbide sizer in a good quality die. This one place where lube in a carbide die makes sense.
venomballistics, do you know the vacant brick building on the SE corner of 60th and Pacific in Omaha? That used to be "Arms and Ammo" until a fire destroyed it sometime in the 1970s and it was never rebuilt. Never opened elsewhere again either. Too bad, because Jim was a fine man to deal with. When I was in High School and frequenting the store he never talked down or acted like a 14-16 year old kid wasn't a worthy customer. Different times and people!!!!!! I miss them all.
For the record, I started shooting a 1911 about 1960, when most GI ammunition available was EC and ECS. Could buy GI hardball bullets for something like 2 cents. My first reloading was steel cases, Pistol 6, (how many of you even heard of this one?), and those GI bullets. Loaded in standard steel RCBS dies (that I still have!). Didn't hurt the dies a bit. This is how I know you only get 2 loadings! Gave it up as a waste of time real quick.