Not all that long ago, “legal Iowa deer rifles” was just a dream.
We were limited by law to using shotguns firing a single projectile (slugs) or muzzleloaders,
Around 10 years ago, the law changed and we could use handguns meeting minimum bore diameter and maximum case length requirements. Pistol caliber rifles were added to the legal firearms for deer hunting in 2017.
In 2020 the Iowa legislature passed a law stating any rifle or cartridge with a minimum bore diameter of .350” and not exceeding .50 cal could be used as long as it had at least 500 ft/lbs of muzzle energy.
This law took effect on July 1, 2020.
The Iowa Natural Resources Commission was opposed to this change and came up with a list of allowable calibers. Most were obsolete and basically the commission tried to end run the law.
Well as of a couple of days ago this list was struck down and the law stands as written.
This makes my 9.3x57, 450/400 3” NE and my sons 450 3 1/4” BPE plus a number of other antique rifles of ours legal for deer hunting in our home state.