When it comes to defining a shotgun, the answer to this question is not if it’s an Any Other Weapon (AOW) or Pistol Grip Firearm (PGF).
Most people assume that a firearm that shoots shotgun shells is a shotgun. As far as the federal law is concerned, however, this isn’t necessarily true.
There are two main categories of standard firearms: long-guns and handguns. Long-guns are firearms that are designed and intended to be fired from your shoulder and are at least 26 inches in overall length. Therefore, if the firearm has a buttstock and is long enough, it is a “long-gun.” However, if the firearm is instead designed to be fired from one hand, then it is a handgun.
There are two sub-categories of long-guns: shotguns and rifles. A shotgun is a long-gun that has a smooth barrel, and a rifle is a long-gun that has a rifled barrel. Therefore, if a firearm has a buttstock, it is over 26 inches long, and it has a smooth barrel, it is a shotgun. If any of those variables change, then the firearm is no longer considered a shotgun under federal law.
Mossberg offers two different types of firearms which are built on shotgun receivers and that fire shotgun shells that aren’t technically shotguns. These are certain models of Mossberg 500s and 590s which have pistol grips without buttstocks and an overall length under 26 inches (Any other Weapons) or over 26 inches (Pistol Grip Firearms).
“Any Other Weapons”
As you’re likely aware, there’s a whole special category of firearms sometimes called “National Firearms Act (NFA) firearms.” This category of firearms includes certain categories of highly-regulated firearms such as short-barreled shotguns (SBS) and “any other weapons” (AOW).
An SBS is a shotgun that has a barrel length less than 18 inches and/or an overall length less than 26 inches. Therefore, if it has a buttstock and a smooth barrel but either the barrel or the overall length aren’t long enough, then it is regulated as an SBS.
However, if that same firearm doesn’t have a buttstock, then the firearm can’t be a shotgun at all - let alone a short-barreled shotgun - because it isn’t designed and intended to be fired from the shoulder. If there’s no buttstock and the overall length is less than 26 inches, then the firearm is technically a handgun.
The AOW category of NFA firearms is a catch-all category that contains a few different types of firearms such as firearms which are “readily concealable” and handguns with a smooth barrel design and are intended to fire shotgun shells.
In this case, the Mossberg Compact Cruiser 500 and 590 are firearms that don’t have a buttstock, are under 26 inches in overall length, and fire shotgun shells. Therefore, they are regulated as NFA firearms, specifically, AOWs.
NFA firearms have extra requirements for manufacture and possession. For example, they all require the payment of a federal tax prior to manufacture or possession and they may have extra restrictions in certain states.
Believe it or not, it is perfectly legal under federal law for most private citizens to manufacture certain NFA firearms for their own use at home. Prior to making an SBS or AOW at home, however, a $200 federal tax must be paid and approval from the ATF must first be obtained. Additionally, local laws vary greatly and must be followed.
When it comes to the purchase of a pre-made NFA firearm, approval must still be obtained from the ATF prior to taking possession of the firearm and a $200 federal tax must be paid for all NFA firearms except AOWs - they only require a $5 tax. This means that it would cost you an additional $200 to make your own AOW at home or you can purchase a Mossberg Compact Cruiser 500 or 590 AOW from your local FFL dealer, and it will only cost you $5 for the transfer.
Mossberg does the work for you and saves you $195!
“Pistol Grip Firearms”
Pistol Grip Firearms (PGF), or “pistol grip only” firearms as they are sometimes called, are another category of non-shotgun “shotguns.” This category includes firearms that have a smooth barrel, are more than 26 inches in overall length, but don’t have a buttstock and therefore can’t be shotguns. They aren’t really handguns either. Instead, the ATF has created this middle-ground category for firearms that are long enough to be a shotgun but don’t have buttstocks.
The good news is that PGFs, unlike AOWs, are standard firearms that don’t have all of the extra restrictions of NFA firearms. This is true even if the PGF has a barrel shorter than 18 inches as long as the overall length is over 26 inches. It can’t be an SBS because, without a buttstock, it isn’t a shotgun. And, because it is over 26 inches, it isn’t a handgun nor is it “readily concealable” so it isn’t an AOW.
It can be tricky to make your own PGF at home - especially if you intend to have a PGF with a barrel length under 18 inches. In order for a PGF with a barrel shorter than 18 inches to be legal, it must have been assembled from a receiver that never had a buttstock attached and it must still be longer than 26 inches in overall length. If the firearm receiver was ever assembled with a buttstock then it was a shotgun at some point and the short barrel would create an SBS, even if the overall length was over 26 inches. Instead, your best bet is to purchase one of Mossberg’s 500 or 590 PGFs that come from the factory without buttstock.
Ryan Cleckner is a former special operations sniper and bestselling author of the Long Range Shooting Handbook. He is currently a firearms attorney at RocketFFL.com