This was almost 20 years ago I really don't recall the specifics. I did deal with this issue years later while working as a law enforcement officer in arnolds park a resort town in the iowa great lakes area but it was a hotel issue not apartments.
yes I said in an earlier post that little or no recourse would include eviction if the clause was enforceable. Just this spring we had a shooting at college apartments 30 miles from my house. It was off campus thankfully no one was killed but at these same apartments a few years ago two women were killed there. So imo eviction is not a big deal. Not having the chance to defend yourself is. (Cedar rapids, kirkwood apartments)
I have never had to rent in iowa or anywhere else but someone brought up ethics and I believe it unethical to deny someone the right to protect themselves and loved ones. Anyone who works or has worked in law enforcement will tell you that they are not there to protect you but to gather evidence at the crime scene to convict your murderer. You are the only one who will protect you and your loved ones.
In iowa posted signs saying no weapons allowed have no legal authority so yes I ignore them. I disarm to go into my fathers office but that's state property and its more out of respect then any legal obligation.