AR-15 Parts
The AR-15 is the most parts-interchangeable firearm platform in history—virtually every component is available aftermarket, and the platform is specifically designed for user-level disassembly and parts replacement. Whether you’re building an AR-15 from scratch, replacing a worn component, or upgrading for competition, Impact Guns carries the full range of AR-15 parts across every sub-category. Our staff helps customers at our Ogden and Boise locations with parts selection and build planning every day.
Browse AR-15 Parts by Category ↓
Lower Receivers and Lower Parts
The AR-15 lower receiver is the serialized component—the part legally considered the firearm. Stripped lowers are blank canvases for custom builds; complete lowers include the entire fire control group, stock, and pistol grip assembled. Lower parts kits contain every small component needed to complete a stripped lower. For a first-time AR-15 builder, a quality stripped lower from Aero Precision or Anderson paired with a lower parts kit and Magpul stock is the most practical starting point. See: AR-15 Lower Receivers.
Barrels
AR-15 barrel length, profile, twist rate, and caliber all directly affect velocity, accuracy, and application. 16″ is the standard legal minimum; 18″ or 20″ adds velocity for precision use. 1:8 twist is the most versatile for common 5.56 bullet weights. Caliber conversions (.300 Blackout, .224 Valkyrie) require only a barrel and bolt change. See: AR-15 Barrels.
Handguards and Rails
M-LOK and Picatinny handguards provide mounting surfaces for lights, lasers, vertical grips, and other accessories. Free-float handguards improve accuracy by eliminating barrel contact. Carbine-length, mid-length, and rifle-length gas systems determine handguard sizing. See: AR-15 Handguards & Rails.
Triggers
Drop-in trigger groups from Geissele, Timney, and CMC are the single most impactful accuracy upgrade for most AR-15s. Two-stage triggers for precision; single-stage for competition speed. See: AR-15 Triggers.
Stocks
Magpul CTR, STR, and MOE stocks eliminate mil-spec buffer tube wobble and improve cheek weld. Luth-AR MBA-1 adds independent length and height adjustment for precision builds. See: AR-15 Stocks.
Grips
Magpul MOE and MIAD grips improve ergonomics and texture over the standard A2. BCM Gunfighter and similar grips optimize angle for competition use. See: AR-15 Grips.
Muzzle Devices
Flash hiders, muzzle brakes, compensators, linear compensators, and suppressor mounts in standard 1/2–28 threads for 5.56 and 9/16–24 for .308. See: AR-15 Muzzle Devices.
Browse by component: Lowers • Barrels • Handguards • Triggers • Stocks • Grips • Muzzle Devices • Stocks
See also: All Gun Parts • AR-15 Rifles • AR-15 Stocks