Free · Builder · Education · Compliance

Build your firearm. Stay legal in your state.

Chambered is a free gun builder and firearm parts compatibility checker that flags restricted components based on your state's laws. Configure an AR-15, 9mm pistol, shotgun, or 1911 — and track the pending firearm legislation that could change what you can own tomorrow.

What are you building?

Pick a category and we'll surface the state laws that actually matter for it. Optionally drop in your location and we'll jump straight to your state's rules.

Built for hobbyists, gunsmiths, and the law-conscious

Six things Chambered does that no spreadsheet or static law page can.

AR-15 build configurator

Match upper, lower, barrel, stock, and magazine across compatible AR-15 platforms. See which parts are restricted in California, New York, Illinois, and other regulated states before you buy.

9mm pistol parts compatibility

Snap frames, slides, barrels, magazines, sights, and trigger groups together and see which combinations meet local barrel-length and magazine-capacity rules.

50-state firearm law database

Search verified state and county-level modification laws — magazine capacity, barrel length, suppressor possession, stock geometry, and feature bans.

Live pending legislation tracker

Real-time feed of state and federal firearm bills sourced from LegiScan. Filter by state and status: introduced, in committee, passed chamber, enacted, or failed.

Interactive education modules

Click parts on the diagram to learn how frames, slides, barrels, lower receivers, upper receivers, and stocks work together. Free for pistol, AR-15, and shotgun platforms.

Source-verified compliance stamp

Every law and bill links back to its official state legislative source. Last-reviewed timestamps and verification metadata are surfaced on every record.

State-by-state firearm modification laws

Tap into verified state-level rules covering magazine capacity, barrel length, suppressor possession, adjustable stocks, and feature bans. We keep every record tied to its official source.

Pending firearm legislation — what could change

Bills currently moving through state legislatures and Congress, refreshed from the LegiScan API. Each one has its own page with status, sponsor, source link, and the latest legislative action.

View all pending bills →

Frequently asked questions

Is Chambered legal advice?

No. Chambered is an educational tool. We surface state firearm laws and pending legislation with links to their official sources, but you should always verify against your local statute or consult an attorney before making purchase or modification decisions.

Does the gun builder cover AR-15, AR-10, AK-47, and 1911 platforms?

Yes. The free tier covers the 9mm pistol, basic AR-15, and basic shotgun platforms. Precision rifle, 1911 pistol, AR-10, AK-47, and revolver platforms are available with a premium account.

Where does the pending firearm legislation data come from?

We sync directly from the LegiScan API, which aggregates bill text and status updates from every U.S. state legislature. Data is refreshed on demand and stamped with the last successful sync timestamp.

Does Chambered handle the actual purchase of firearm parts?

No. Chambered is a configurator and compatibility checker only. Each part in the builder links to the retailer carrying it; you complete the purchase on their site and through a licensed FFL where required.

How are restricted parts identified?

Each part in the catalog can carry a jurisdiction-specific restriction referencing the relevant state law (e.g., California pistol barrel-length rules, Cook County magazine-capacity limits, New York suppressor prohibition). The restriction popup includes the source link.