There is definitely a difference in the brass... the dot-FC-dot brass is extruded and likely comes out of the exact same machine that spits out all CCI, Speer and Blazer headstamped 9mm brass.
The FC stuff is a more standard brass like we've grown used to seeing.
Is there a difference in case capacity or could you notice a difference in shooting them? I would doubt it, simply because we are talking about 9mm handgun here... but I suppose it's possible.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.