Any Other Weapons (AOWs): The $5 NFA Category Explained

Any Other Weapon (AOW) is a catch-all NFA category for concealable or unusual weapons that do not fit the definitions of a rifle, shotgun, machine gun, suppressor, or destructive device. Examples include pen guns, cane guns, certain smooth-bore pistols, and firearms disguised as everyday objects.

The AOW category has one quirk that surprises people: while every other NFA transfer costs a $200 tax stamp, transferring an AOW costs only $5. This guide explains what qualifies, the unusual tax structure, and the practical rules.

This is general information, not legal advice; verify with the ATF or a qualified attorney.

What qualifies as an AOW

The NFA defines AOWs as weapons capable of being concealed on the person from which a shot can be discharged through the energy of an explosive, plus a handful of specific designs. In practice, the category captures items like pen guns, cane guns, wallet holsters that fire, smooth-bore handguns, and pistols with certain forward vertical grips.

A common surprise: adding a vertical foregrip to a pistol can turn it into an AOW, because a handgun is designed to be gripped with one hand, and the foregrip changes its classification.

The $5 transfer tax quirk

AOWs are the one NFA category where the transfer tax is $5 rather than $200. This applies when an AOW is transferred to you on a Form 4 from a dealer.

Note the asymmetry: making an AOW yourself on a Form 1 costs the full $200 making tax. So the $5 rate applies to transfers, not to manufacture.

AOW transfer (Form 4): $5 tax stamp
AOW making (Form 1): $200 making tax
All other NFA transfers: $200

Buying an AOW

Buying an AOW works like any other NFA item: complete a Form 4 with your dealer, pay the (reduced) $5 tax, submit fingerprints and a photo, and provide CLEO notification. The dealer holds the AOW until the ATF approves the transfer.

Because of the eForms improvements since 2024, AOW transfers filed electronically are often approved in days to weeks.

Transport and everyday rules

Unlike SBRs, SBSs, and machine guns, AOWs do not require an approved Form 5320.20 to be transported across state lines. In that respect they behave like suppressors for travel purposes.

Still, keep a copy of your approved paperwork with the item, and remember AOWs remain registered NFA firearms subject to the usual possession rules.

State-law variance

State treatment of AOWs varies, and some states restrict concealable or disguised firearms independently of the NFA. Confirm your state allows the specific item before purchasing. Our state NFA reference is a useful starting point, though AOW-specific rules can be nuanced.

Frequently asked questions

Why is the AOW transfer tax only $5?

It is simply how the NFA's tax schedule was written: transfers of AOWs are taxed at $5, while transfers of other NFA firearms are taxed at $200. Note that making an AOW yourself still costs the full $200 making tax.

Does adding a foregrip to my pistol create an AOW?

Often, yes. A handgun is designed to be fired with one hand, so adding a vertical foregrip can reclassify it as an AOW under the NFA. Registering and paying the tax stamp before making that change keeps you compliant.

Do AOWs require transport approval across state lines?

No. Like suppressors, AOWs are exempt from the Form 5320.20 interstate transport requirement that applies to SBRs, SBSs, and machine guns. Confirm the item is legal in your destination state before traveling.

Can I make my own AOW cheaply because of the $5 tax?

No. The $5 rate applies only to transfers. Making an AOW yourself on a Form 1 costs the standard $200 making tax, the same as making an SBR or SBS.

Last reviewed 2026-07-07.