724.1  Offensive weapons.
  An offensive weapon is any device or instrumentality of the following types:
  1.  A machine gun. A machine gun is a firearm which shoots or is designed to shoot more than one shot, without manual reloading, by a single function of the trigger.
  2.  A short-barreled rifle or short-barreled shotgun. A short-barreled rifle or short-barreled shotgun is a rifle with a barrel or barrels less than sixteen inches in length or a shotgun with a barrel or barrels less than eighteen inches in length, as measured from the face of the closed bolt or standing breech to the muzzle, or any rifle or shotgun with an overall length less than twenty-six inches.
  3.  Any weapon other than a shotgun or muzzle loading rifle, cannon, pistol, revolver or musket, which fires or can be made to fire a projectile by the explosion of a propellant charge, which has a barrel or tube with the bore of more than six-tenths of an inch in diameter, or the ammunition or projectile therefor, but not including antique weapons kept for display or lawful shooting.
  4.  A bomb, grenade, or mine, whether explosive, incendiary, or poison gas; any rocket having a propellant charge of more than four ounces; any missile having an explosive charge of more than one-quarter ounce; or any device similar to any of these.
  5.  A ballistic knife. A ballistic knife is a knife with a detachable blade which is propelled by a spring-operated mechanism, elastic material, or compressed gas.
  6.  Any part or combination of parts either designed or intended to be used to convert any device into an offensive weapon as described in subsections 1 to 5 of this section, or to assemble into such an offensive weapon, except magazines or other parts, ammunition, or ammunition components used in common with lawful sporting firearms or parts including but not limited to barrels suitable for refitting to sporting firearms.
  7.  Any bullet or projectile containing any explosive mixture or chemical compound capable of exploding or detonating prior to or upon impact, or any shotshell or cartridge containing exothermic pyrophoric misch metal as a projectile which is designed to throw or project a flame or fireball to simulate a flamethrower.
  Notwithstanding section 724.2, no person is authorized to possess in this state a shotshell or cartridge intended to project a flame or fireball of the type described in this section.
  8.  Any mechanical device specifically constructed and designed so that when attached to a firearm silences, muffles, or suppresses the sound when fired. However, this subsection does not apply to a mechanical device possessed and used by a person solely for the purpose of shooting a deer pursuant to an approved city special deer population control plan if the person has a valid federal permit to possess and use the mechanical device.
  9.  An offensive weapon or part or combination of parts therefor shall not include the following:
  a.  An antique firearm. An antique firearm is any firearm (including any firearm with a matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898 or any firearm which is a replica of such a firearm if such replica is not designed or redesigned for using conventional rimfire or centerfire ammunition or which uses only rimfire or centerfire fixed ammunition which is no longer manufactured in the United States and which is not readily available in the ordinary channels of commercial trade.
  b.  A collector’s item. A collector’s item is any firearm other than a machine gun that by reason of its date of manufacture, value, design, and other characteristics is not likely to be used as a weapon. The commissioner of public safety shall designate by rule firearms which the commissioner determines to be collector’s items and shall revise or update the list of firearms at least annually.
  c.  Any device which is not designed or redesigned for use as a weapon; any device which is designed solely for use as a signaling, pyrotechnic, line-throwing, safety, or similar device; or any firearm which is unserviceable by reason of being unable to discharge a shot by means of an explosive and is incapable of being readily restored to a firing condition.
[C27, 31, 35, §12960-b1; C39, §12960.01; C46, 50, 54, 58, 62, 66, §696.1; C71, 73, 75, 77, §696.1, 697.10, 697.11; C79, 81, §724.1]
83 Acts, ch 7, §1; 88 Acts, ch 1164, §2, 3; 92 Acts, ch 1004, §1, 2; 2000 Acts, ch 1116, §7