Gun Tools/Updated 09.15.26/8 tools
Gun Part Compatibility Checkers and AR-15 Calculators
Compatibility checkers, tuning calculators and legal length checks that end in parts you can actually buy. Every result is drawn from the live catalog and the parts people configure here, not from a static table.
Build planning tools
Price the build before the first part ships.1
Compatibility checkers
What fits what, checked against the parts we track.3
ToolMuzzle Thread Checker
Pick your barrel's caliber and platform, get the standard thread pitch, and see every muzzle device and suppressor in the catalog that actually threads on, with live prices.
ToolFRT and Binary Trigger Picker
Choose your platform and see every forced reset trigger, binary trigger and Super Safety the catalog carries for it, what the host needs to run one, and where each is in stock.
ToolGlock Red Dot Fit Checker
Pick how your Glock slide is cut and see which red dots mount directly, which need a plate, and the plates and optics in stock right now.
Tuning calculators
The numbers behind a gun that runs.2
ToolTwist Rate Calculator
Pick a bullet and a twist rate, get the Miller stability factor, then see barrels with that twist and ammo loaded with that bullet, with today's price per round.
ToolBuffer Weight Calculator
Enter your gas system, barrel length, buffer tube and ammo, add a suppressor or a fast trigger, and get the buffer weight to start with plus the buffers in stock that match.
Legal length checks
Where the federal lines are before you build.2
ToolGun Travel Checker
Can I bring my gun to another state? Pick where you start, where you are going and what is coming along: carry pistol, AR-15, magazines, suppressor, SBR, brace, forced reset or binary trigger, hollow points. Every state on the route is checked for transporting firearms across state lines: magazine limits, assault weapon bans, NFA rules, carry permit type and trigger bans, with what to do before the state line.
ToolBarrel and Overall Length Checker
Enter barrel length, muzzle device and how the back end is configured, and see whether the build is a rifle, a short barreled rifle, a pistol or an AOW under federal law, with the barrels in stock at that length.
Already on the site
- AR-15 Builder with compatibility checks on every slot
- Glock Builder model, generation and cut aware
- Ammo Finder cost per round, refreshed daily
- Gun Laws by State all 50 states, ten rules each