Well, since I'm using floor sweepings for 9mm I've run into some problems with case bulges.
There are a number of threads on this in THR and other forums, no need to rehash all of them. If you're interested just Google it (or Bing, or Ask, or Yahoo, or DogPile). I'm not convinced it's caused by one particular gun or even design. And I don't care, what causes it, really. I'm not going to pay for 9mm brass and I'm not going to turn down free stuff.
The long and short, if you've never loaded 9mm and are considering it, is that you need to check your cases after resizing. you'll need to resize them as one step then check them in a chamber checker. (or in your guns barrel -- remove from gun first) Then finished the reloading process sans the resizing die. (Oh how I love the LnL, cause it only takes seconds to add/remove dies.)
I bought the ECW chamber checker with 7 chambers from Dillion.
And while this slows down the reloading process, with a progressive it still goes pretty fast. I only have to feed in the cases, the press does the ejecting when they come around to the last station.
Oh and I also discovered that my Lone Wolf 40 to 9mm barrel for my Glock 23 has a "match" chamber. Meaning it's pretty tight on tolerances. Some rounds that might just make it through the chamber checker still won't chamber in that barrel. I corresponded with Wolf and they confirmed that their chambers are NOT "loose". They will however ream them out to match your ammo for $25. Just send them 5 resized shells. I thought that was very cool. I don't shoot the 23 that much to worry about it and when I do it'll probably be factory ammo.