I called the DNR and got a copy of a portion of 2017-18 Iowa Hunting Regulations
LEGAL METHOD OF TAKE
Archery: Longbows, recurve bows, and compound bows shooting broadhead arrows are permitted. No explosive or chemical devices may be attached to the arrow or broadhead. There are no minimum draw weights for bows or minimum diameter for broadheads. Arrows must be at least 18 inches long. Draw locks on compound bows are legal.
Crossbows are not legal except that a physically handicapped person, as defined on p. 13, may obtain a permit from the DNR to use a crossbow. Applications are available at
www.iowadnr.gov/hunting - click on “Licenses and Laws” and then on “License Applications,” or by visiting the DNR central office or any of the district offices (p. 45), or by calling the DNR at 515-725-8200. Residents 70 and older may obtain one Antlerless-only statewide crossbow deer license. See p. 34 for details. Hunters may not carry a handgun while hunting under an archery tag, unless they have an unfilled transportation tag for a season that allows handguns or a valid permit to carry.
Shotguns: 10-, 12-, 16-, and 20-gauge shotguns shooting single slugs only.
Muzzleloaders: Flintlock or percussion cap muzzleloading rifles or muskets between .44 and .775 caliber shooting single projectiles; muzzleloading pistols .44 caliber or larger with a minimum barrel length of 4 inches and no shoulder stock or long barrel modifications. Muzzleloaders equipped with electronic ignition are not allowed. There are no restrictions on in-line or disk-type muzzleloaders. Riflescopes may also be used.
Handguns/Rifles: Center-fire handguns .357 caliber or larger, and rifles shooting straight wall ammunition with an expanding-type bullet. Mini-mum barrel length for all handguns is 4 inches. No shoulder stock or long barrel modifications are allowed in late muzzleloader season.
Hunters age 16 and under may not use any handguns. Hunters ages 17 through 20 must be accompanied by a parent, guardian or spouse who is at least 21 years old to use a handgun.
The following center-fire cartridges may be used, along with others not identified in this list that meet the straight-walled cartridge criteria in the next section below: .357 Magnum, .357 Maximum, .375 Winchester, .38 Super, .40 S&W, .401 Powermag, 10 mm Auto, .41 Remington Magnum, .41 Action Express, .44 S&W Special, .44 Remington Magnum, .44 Automag, .444 Marlin, .445 Super Mag, .45 ACP, .45 Colt, .45 Super Mag, .45 Winchester Magnum, .45 Silhouette, .450 Bushmaster, .451 Detonics, .454 Casull, .45-70 Govt., .460 Rowland, .460 S&W Mag, .475 Widley Magnum, .475 Linebaugh, .480 Ruger, .50 Action Express, .50 Linebaugh, .50 Beowulf and .500 S&W Mag.
Allowable Straight-walled Cartridge Criteria:
■■Center-fired straight-walled rimless cartridges chambered for handgun use with bullets from 0.357” to 0.500” diameter and a case length from 0.850” to 1.800.”
■■Center-fired straight-walled rimmed cartridges chambered for handgun use with bullets from 0.357” to 0.500” diameter with a case length from 1.285” to 1.800.”
Crossbow: A legal weapon for residents during the Late Muzzleloader season. A crossbow consists of a bow mounted transversely on a stock or frame and designed to fire a bolt, arrow or quarrel by the release of the bow string, which is controlled by a mechanical trigger and working safety. Crossbows equipped with pistol grips and designed to be fired with one hand are illegal for taking or attempting to take deer or turkey. All projectiles used in conjunction with a crossbow for deer.