Buyer's Notes
Do I Need an FFL?
On every build sheet on this site, exactly one line is flagged FFL. That part is legally the firearm and it goes through a dealer. Every other part on the list ships to your door like a toaster. Once that clicks, the whole process stops being intimidating.
The one-part rule
Federal law doesn't regulate "guns" as whole objects. It regulates a single component: the frame or receiver. That part carries the serial number, that part is what the paperwork follows, and in the eyes of the law that part is the firearm even when it's a bare shell with no barrel, no trigger and no ability to fire anything at all.
Everything bolted to it is just hardware. A barrel is hardware. A bolt carrier group is hardware. A $900 optic is hardware. None of it is tracked, none of it needs a background check, and all of it arrives in a cardboard box with your name on it.
So the question is never "do I need an FFL for this build?" The answer is always yes, once, for one part. The useful question is which part, and the answer depends on the platform.
Which part it is, by platform
This is the whole table. It matches the FFL flag on every build sheet here.
| Build | The serialized part | What that means in practice |
|---|---|---|
| AR-15 | Stripped lower receiver | The small aluminum part with the trigger and magwell. The upper, barrel and everything else ship to you. |
| AR-10 / .308 | Stripped lower receiver | Same as AR-15, but pattern matters enormously. See the pattern guide. |
| AK-47 / AKM | Receiver | Usually bought as a barreled, riveted receiver or a complete rifle. Raw kits are gunsmith work. |
| Glock 17 / 19 | Frame | The polymer grip half. Slide, barrel and internals all ship to your door. |
| SIG P320 | Fire Control Unit (FCU) | The little stainless chassis. This is why one FCU can become a full-size, carry or X-series gun. |
| 1911 | Frame | Slide, barrel, small parts and grips all ship to you. |
| Ruger 10/22 | Receiver | Aftermarket receivers are serialized too, not just Ruger factory ones. |
Notice the P320 row. Because SIG made the serialized part a self-contained chassis rather than the grip, the P320 is the one build on this site where you can legally own one registered part and swap the entire exterior of the gun around it whenever you feel like it. That's a genuine design advantage, not marketing.
What ships straight to your door
Everything below arrives at your address with no dealer, no 4473 and no background check:
- Barrels, of any length that's legal for the configuration you're building.
- Bolt carrier groups, bolts, charging handles, gas blocks and gas tubes.
- Uppers, including complete assembled uppers with the barrel already installed.
- Triggers, lower parts kits, safeties, springs and pins.
- Handguards, rails, stocks, buffer tubes, grips and furniture.
- Optics, mounts, lights, slings and every other accessory.
- Magazines, subject to your state's capacity limits.
- Slides, slide completion kits, frames parts kits and sights on the pistol builds.
A complete AR-15 upper is not a firearm. It has the barrel, the chamber, the bolt and the charging handle, and it still ships to your porch, because the receiver that the law cares about is the lower. People find this hard to believe the first time. It's correct.
How a transfer actually works
Start to finish, the first time takes about ten minutes of thinking and twenty minutes at a counter.
- Find a local dealer first, before you order. Any gun shop, most ranges, a lot of pawn shops. Call and ask: "Do you accept transfers, what's your fee, and do you need anything from the shipper?"
- Get their FFL on file with the retailer. Most big retailers keep a library of dealer licenses and many shops will email theirs directly. This is the step that trips people up, and it's clerical, not legal.
- Order, and ship it to the shop's address, not yours. The retailer's checkout will have a field for this.
- Wait for the shop to call. They'll log it in when it arrives.
- Go in with your ID. You fill out ATF Form 4473 at the counter, they run the background check, and in most cases it comes back in minutes.
- Pay the transfer fee and walk out with your receiver. Now build the rest at your kitchen table.
That's it. It is the same process as buying a complete rifle off the rack, because legally it is the same process.
What it costs and how to pay less
Transfer fees run roughly $25 to $50 per firearm. That number is set by the shop, not by law, and it varies more than people expect within a single town.
- Call three places. A $25 spread on a $80 receiver is real money on a budget build.
- Ask about the stripped-receiver policy specifically. A minority of shops won't transfer stripped lowers, or charge extra for them, because they'd rather sell you a complete rifle.
- Ranges and pawn shops are often cheaper than dedicated gun stores, because transfers are a side business rather than a competitor to their inventory.
- Batch it. Some shops charge a lower per-unit fee if two receivers land in the same shipment. If you're building two rifles, order together.
- Don't chase a $20 saving across town. A shop that answers the phone, logs things in promptly and calls you the day it arrives is worth the extra twenty.
Five things people get wrong
"I need to get an FFL." No. An FFL is a business license held by a dealer. You are not applying for anything. You are just choosing which shop receives your package.
"The whole build has to go through the dealer." No. One part. The rest is mail order.
"A stripped lower isn't really a gun, so it can ship to me." It is, legally, and it can't. This is not a grey area and retailers will not do it.
"Building my own means there's no paperwork." There is exactly as much paperwork as buying a finished rifle: one 4473 on one receiver. Building changes the parts, not the law.
"I can have a friend in another state send me one." Interstate transfers go dealer to dealer. This is one of the easier ways for a well-meaning person to commit a felony, so don't improvise here.
The 80% question
You'll see "80%" frames and receivers advertised as a way around all of the above. The honest summary, which is less exciting than the marketing:
A partially-complete frame or receiver used to sit outside the definition of a firearm, which is where the route's reputation came from. Under a 2022 ATF rule, a kit sold with a jig or the tooling to finish it is treated as a firearm and goes through a dealer like anything else, and the Supreme Court upheld that rule in 2025. On top of federal law, several states ban the route outright, and a few treat possession of an unserialized frame as a crime regardless of how it was acquired.
This is the one topic on this site where we'd rather you close the tab and go read a current primary source. Rules here have changed twice in recent years and vary hard by state. Nothing on this page is legal advice. If you're considering an 80% build, check current ATF guidance and your own state's statute first, and understand that "it was legal when I bought it" is not a defense anyone enjoys testing.
For almost everyone reading this, a serialized frame through a dealer is cheaper, faster, legally boring and produces a normal transferable gun you can sell later. That's the route the build sheets assume.
FAQ
Which part of a gun build requires an FFL?
The frame or receiver. On an AR-15 or AR-10 it's the lower receiver, on a Glock-pattern pistol it's the frame, on a SIG P320 it's the fire control unit, on a 1911 it's the frame, on an AK it's the receiver, and on a Ruger 10/22 it's the receiver. Every other part on the build ships directly to your door.
Can I buy a barrel or a bolt carrier group without an FFL?
Yes. Barrels, bolt carrier groups, triggers, handguards, stocks, optics, magazines and every other non-serialized component ship straight to your address with no dealer and no background check, subject to your state's own rules on things like magazine capacity.
How much does an FFL transfer cost?
Typically $25 to $50 per firearm, set by the dealer, not by law. Call ahead, because some shops charge more for online orders and a few refuse transfers of stripped receivers entirely. Some ranges and pawn shops run cheaper than gun stores.
Do I need an FFL to buy a stripped lower receiver?
Yes. A stripped lower receiver is legally a firearm even though it's an empty piece of aluminum with no barrel, no trigger and no way to fire anything. It ships to a dealer, you fill out a 4473 and pass a background check there, exactly as if you were buying a complete rifle.
Is an FFL something I apply for as an individual?
No, and this is the single most common misunderstanding. An FFL is a license held by a dealer or manufacturer as a business. As a buyer you never get one. You simply pick a local shop that has one and have your receiver shipped there.
What about 80% frames and receivers?
The rules changed. Under a 2022 ATF rule, partially-complete frames and receivers sold with a jig or tooling are treated as firearms and go through a dealer like anything else, and the Supreme Court upheld that rule in 2025. Several states ban the route outright regardless of federal law. Check current federal guidance and your own state's law before buying one.
Can a receiver be shipped to my house if I live in another state?
No. Interstate transfers of firearms go dealer-to-dealer, so the receiver ships to an FFL in your state and you collect it there. Handgun frames additionally have to be transferred by a dealer in your own state of residence.
Now go pick a build
Every build sheet flags the serialized part on the first line, so you always know which one line goes to a dealer and which ones land on your porch.
See the build sheets →Affiliate disclosure: Cold Bore Index earns a commission when you buy through links on this site, at no extra cost to you. We link to real products at retailers you already use; prices and availability are shown live on their pages. We're not a dealer and hold no inventory. Nothing here is legal advice.