A Stripped Lower Is a Firearm: Transfers, Serial Numbers and What Ships to Your Door

The AR-15 is a rifle you can buy in pieces, and the piece that matters legally is the lower receiver. It is the part that carries the serial number, the part the federal government defines as the firearm, and the only part of a build that has to go through a licensed dealer. Everything else, the upper, the barrel, the bolt carrier, the trigger, the stock, the grip and the small parts, is a part and ships to your door. This guide explains what that means when you order from us, what happens at the dealer, and the choices you make at the counter that follow the lower for its whole life.

What the law regulates

Under the Gun Control Act a firearm is the frame or receiver, and for an AR-pattern rifle the ATF treats the lower receiver as the receiver. A stripped lower, a bare forging with nothing in it, is legally identical to a complete rifle: it must be serialized by its maker, it must be sold by a dealer, and the buyer must complete ATF Form 4473 and pass a background check. A complete lower with the trigger, stock and grip installed is the same thing with more parts attached. Every lower in our catalogue is a serialized, manufacturer-marked receiver from a licensed maker, and every one transfers through the dealer you name at checkout.

What we do not sell

We do not sell unfinished receivers, receiver blanks or the tooling to complete them, and we do not sell any part intended to convert a rifle to automatic fire. The lowers here are finished, serialized and transferred like any other firearm. That keeps every build on this site inside the same legal framework as a rifle bought off a shop wall.

The transfer

Choose a licensed dealer near you that accepts inbound transfers and ask their fee, usually twenty to seventy-five dollars. Name them at checkout; we confirm their licence against the ATF's public list and ship the lower to them. When it arrives you bring government photo identification with your current address and any card or permit your state requires, complete Form 4473, and the dealer runs the check. Most checks clear in minutes. Federal law lets a dealer transfer a lower receiver to a buyer of 21 or older; the age is 21 rather than 18 because a bare receiver is classed as an "other" firearm rather than a rifle on the form, and dealers apply the handgun age to it. A complete rifle from us may go to a buyer of 18 in states that allow it.

Rifle, pistol or other

Form 4473 asks the dealer to record what the firearm is. A stripped lower is recorded as "other", which leaves you free to build it as a rifle with a sixteen-inch barrel and a stock, or as a pistol with a shorter barrel and no stock, or with a brace. That flexibility is why many builders prefer a stripped lower to a complete one. A complete lower sold with a stock already fitted is recorded as a rifle, and a receiver that has been a rifle should stay one: assembling it with a barrel under sixteen inches and a stock creates a short-barrelled rifle, which is a registered item under federal law. Our complete lowers come with either a stock or a brace, and the listing says which.

Braces and short barrels in 2026

The federal rule that treated a braced pistol as a short-barrelled rifle was vacated by a federal court in June 2024, the government dropped its appeal in July 2025, and in 2026 the ATF proposed formally removing it. As of September 2026 a pistol with a stabilising brace is treated as a pistol under federal law, though the ATF has said it keeps case-by-case authority over configurations clearly designed to be shouldered. Some states have their own rules on braces and on pistols with detachable magazines; check yours before you build a pistol-length AR.

What states add

Most of the states we ship to add nothing to the federal transfer. Florida requires the buyer to be 21 and imposes a waiting period of three business days, or five in some counties, unless an exemption applies. Pennsylvania runs its own instant check alongside the federal one. Iowa's permit to acquire is optional. Several states outside our main footprint restrict AR-pattern rifles by feature, cap magazine capacity or, in a few cases, require lowers to be registered; our checkout holds every order to what a dealer in your state may lawfully transfer, and the city pages summarise the rules for each state.

Parts ship to your door

Lower parts kits, triggers, safety selectors, magazine catches and bolt catches.
Buffer tubes, buffers, springs, stocks, braces and grips.
Complete uppers, stripped uppers, barrels, handguards, bolt carrier groups and charging handles.
Magazines, where your state does not cap capacity below the magazine's.

An upper receiver is not a firearm under federal law, so a complete upper with a barrel and bolt carrier ships to your address. Pair it with a lower you already own and you have a rifle without a second transfer.

Keeping records

Write down the lower's serial number and maker somewhere other than the safe. There is no federal registration of lowers and none of our states require it, but a serial number is what recovers a stolen receiver and what a dealer will ask for if you ever sell it through them. Keep the invoice with it.

With the legal part settled, the build starts with the rifle-or-pistol decision, then the parts kit, the buffer system and the controls. Browse lowers in the catalogue.

General information, not legal advice. Current as of September 2026. Laws change; check the official source before you act.