My name is XXXXX XXXXX I'm a criminal
If you have been convicted of a crime for which the maximum possible penalty is more than a year -- not how much time you got but what would have been your worst case scenario -- then you lose both your state and your Federal firearms rights.
In Iowa, a felony conviction would mean that you cannot own, possess, or be anywhere near a firearm, anywhere in the country.
If however, you had a deferred disposition, meaning that at the close of your probation, your case was dismissed, then you get the right to say that you have no felony convictions and you should still have your state gun rights.
The interaction between states and the Federal government in this area is very tricky. By that I mean that while the State may see this as a dismissal and allow you your firearms rights, a felony conviction costs you your federal rights too. And if you had to plead guilty to this felony before ultimately getting it dismissed, the Federal government may consider that a Felony for purposes of your gun rights.
That means that you could be unable to pass the NICS check if you were to go buy a weapon. If that happens you could appeal the decision to the FBI gun unit. (see link)
And you would have to give official proof that your case was dismissed and you had state gun rights. If the appeal doesn't work, you'd need a pardon from the governor to have gun rights again.