This from Iowa DNR website....
Legal firearms for the youth/disabled and shotgun 1 and 2 seasons include:
Pistols and revolvers (with a minimum barrel length of 4 inches)
Straight-wall and "necked-down" cartridge rifles shooting an expanding type bullet of at least .350 inches and no greater than .500 inches with at least 500 foot pounds of muzzle energy.
This includes, but is not limited to, the following common calibers: .35 Whelen, .350 Legend, .358 Winchester, .375 Winchester, .40 S&W, .44 Magnum, .444 Marlin, .45 Long Colt, .45 Raptor, .450 Bushmaster, .450 Marlin, .45-70 Govt, .460 S&W and .500 S&W.
If you’re not sure if your cartridge is allowed, please check with your local DNR conservation officer.
All of them, as long as they have a bullet diameter between 0.350 inches and 0.500 inches.
