Frequently Asked Questions

No. We don't sell anything. You plan the build here, and every buy link goes to the retailer or maker, where you check out as usual.

No. There is nothing to sign up for. Builds you save are kept in your browser, and Copy Link gives you a link that opens the same build on any other device.

The AR-15 and AR-10 rifles, the Glock 17, 19 and 26, the Glock 43X and 48, the Glock 20 and 21, the Sig P320, the Sig P365, the S&W M&P 2.0 and the Springfield Hellcat. More platforms are on the way.

Some retailer links may earn us a small commission at no extra cost to you. It never changes which parts we show or how we check fit.

Each part carries its real measurements and the maker's own fit notes, and the builder checks every part against the rest of your build. Always confirm fit with the maker before you buy.

Conflict means the part won't work with something already in your build. Check means it can work but needs something extra, like an adapter plate, or a second look at the maker's fit notes. Note is useful information that doesn't change whether it fits.

Things worth knowing about the build as a whole, like extra flash and blast from a short barrel, a light trigger pull, or ammo that must never go in that chamber. None of them stop the build from working.

For each platform we put together three complete, compatible builds: Budget, Best Value and Premium. Open one in the builder and swap any part you like.

Drawings are drawn to each part's real proportions from published dimensions and patent drawings, so they show how the build will look. They aren't for machining. Weights marked ≈ include estimates until we confirm the makers' listed weights.

Yes. Copy Link gives you a link that opens the exact build. A complete build with no conflicts can also be shared on the Community page, where other builders can vote on it.

Each week the builds with the most votes, and the most people clicking through to buy the parts, are featured at the top of the Community page.

We check retailer and maker sites every night where they allow it, and show each part's price at every retailer we track. Prices marked Sample aren't tracked yet, so always confirm the price at the retailer.

Some retailers don't allow automated price checks, and we respect that. We add retailers as they make their prices available to us.

Save a build to My Builds, then enter your email there. We send one email a day at most, only when a part in a saved build moves by $20 and 10% or more. Every email has a one-click unsubscribe link.

We only use it to send the price alerts you asked for. We don't sell it or share it, and unsubscribing deletes it.

FFL marks the serialized part, which is legally the firearm (a pistol frame or fire control unit, or an AR lower receiver). It ships to a licensed dealer near you, who handles the transfer and background check.

Not always. Some states limit magazine capacity, muzzle devices or other features, and retailers will not ship restricted items there. Check your state and local laws before you buy.

Laws vary by country, state and city, and they change. We don't give legal advice, so check the rules where you live, and buy the serialized part through a licensed dealer.