Let's examine the NFA implications...
chesterfield said:
Wouldn't this fall into the "any other weapon" category?
If the propulsion is solely electromagnetic, IMHO clearly no. My emphasis in
boldface:
26 U.S. Code § 5845(e) said:
The term “any other weapon” means any weapon or device capable of being concealed on the person from which a shot can be discharged through the energy of an explosive, a pistol or revolver having a barrel with a smooth bore designed or redesigned to fire a fixed shotgun shell, weapons with combination shotgun and rifle barrels 12 inches or more, less than 18 inches in length, from which only a single discharge can be made from either barrel without manual reloading, and shall include any such weapon which may be readily restored to fire. Such term shall not include a pistol or a revolver having a rifled bore, or rifled bores, or weapons designed, made, or intended to be fired from the shoulder and not capable of firing fixed ammunition.
The first category expressly specifies that the propellant must be an explosive. The second category is a "pistol or revolver", which an electromagnetic rail gun clearly is not. The third category has "combination shotgun and rifle barrels", so this also clearly refers to a traditional firearm.
OTOH there IS a possibility that a rail gun could be categorized as a destructive device (DD) if it is constructed in a particular way:
26 U.S. Code § 5845(f) said:
The term “destructive device” means:
(1) any explosive, incendiary, or poison gas
(A) bomb,
(B) grenade,
(C) rocket having a propellent charge of more than four ounces,
(D) missile having an explosive or incendiary charge of more than one-quarter ounce,
(E) mine, or
(F) similar device;
(2) any type of weapon by whatever name known which will, or which may be readily converted to, expel a projectile by the action of an explosive or other propellant, the barrel or barrels of which have a bore of more than one-half inch in diameter, except a shotgun or shotgun shell which the Secretary finds is generally recognized as particularly suitable for sporting purposes; and
(3) any combination of parts either designed or intended for use in converting any device into a destructive device as defined in subparagraphs (1) and (2) and from which a destructive device may be readily assembled. The term “destructive device” shall not include any device which is neither designed nor redesigned for use as a weapon; any device, although originally designed for use as a weapon, which is redesigned for use as a signaling, pyrotechnic, line throwing, safety, or similar device; surplus ordnance sold, loaned, or given by the Secretary of the Army pursuant to the provisions of section 4684 (2), 4685, or 4686 of title 10 of the United States Code; or any other device which the Secretary finds is not likely to be used as a weapon, or is an antique or is a rifle which the owner intends to use solely for sporting purposes.
Under subsection (1), if the rail gun projectile carries a "explosive, incendiary, or poison gas" charge, it could be considered a "similar device" to a "missile having an explosive or incendiary charge of more than one-quarter ounce"; however, this may only apply to the
projectile, and
not to the launcher itself. [This is not without precedent, as a live hand grenade is considered a DD, but the user's arm obviously is not.
]
Subsection (2) is clearly written to apply to devices invented after the NFA was enacted ("...any type of weapon by whatever name known..." that uses a non-specific "other propellant"). However, this provision ONLY applies if the device has at least one "barrel... which [has] a bore of more than one-half inch in diameter".
[EDIT TO ADD] Subcategory (3) specifically exempts a "device which is neither designed nor redesigned for use as a weapon"; however, it's not always clear where the line is drawn, and it can depend on the
user's intent.
Previous vague guidance from the ATF has stated that >1/2"-bore potato cannons or spud guns are not considered firearms or DD's,
provided that they are not used as weapons or loaded with explosive or incendiary projectiles. However, if someone were to threaten another person with one, all bets would be off. IOW it's somewhat of a legal gray area. YMMV and caveat emptor.
