At 3CR Tactical, we offer a wide selection of AR parts kits to help you build, upgrade, or maintain your AR-15 platform. Whether you’re a first-time builder or an experienced firearm enthusiast, our high-quality parts kits provide everything you need to customize your rifle to your exact specifications. From lower parts kits to complete build kits, we’ve got you covered.
AR barrels for 5.56 NATO, .223, 9mm PCC, and .308/AR-10 builds — carbine, mid-length, and rifle gas systems in M4 and government profiles. Free shipping, live stock.
Complete the build with a buffer tube and kit.
Free shipping on every order, and stock levels shown are live.
At 3CR Tactical, we appreciate the critical role AR bolts play in your firearm’s performance and reliability. We’ve meticulously curated our selection to offer you a range of AR bolts that cater to your specific needs. Dive into our collection and discover the foundation of a dependable and efficient firearm.
Buffer tubes, buffers, springs, and complete kits for AR-15, AR-9 (9mm PCC), and AR-10/.308 builds — carbine, rifle, and pistol configurations. Free shipping with live stock counts.
Completing the build? Browse AR barrels and parts.
Free shipping on every order, and stock levels shown are live.
Building your own AR-15 is one of the most rewarding experiences for firearm enthusiasts, and at 3CR Tactical, we make the process easier with our high-quality AR build kits. Whether you’re a seasoned builder or new to the world of firearms assembly, our kits provide everything you need to craft a fully functional, reliable, and customizable AR-15 from scratch.
When it comes to enhancing the performance and ergonomics of your AR platform, the choice of a butt stock is a critical decision. 3CR Tactical proudly presents a wide selection of AR butt stocks to cater to the diverse needs and preferences of firearm enthusiasts. Explore our extensive collection of butt stocks, each designed with precision and quality in mind.
AR-15 and AR-10 charging handles — mil-spec replacements, ambidextrous upgrades, extended-latch options. Inventory covers the 5.56/.223 platform and the .308/7.62 LR platform. Pick by platform and how you run the gun.
Your charging handle and bolt carrier group work as a system — a sticky BCG makes any handle feel heavy. If you are upgrading the handle because charging feels gritty, check the BCG first. Our BCG guide covers what to look for. If you are building from scratch, see our sub-$400 AR-15 build list for a sane parts breakdown.
AR Gas blocks, gas tubes and other parts related to the direct impingement mechanism of the AR platform.
AR-15 grips covering both the rear pistol grip on your lower receiver and the forward grip mounted on your handguard or rail. Inventory includes ergonomic pistol grips, vertical foregrips, angled foregrips, and grips with integrated lights or laser modules.
The rear pistol grip is the grip on your AR-15 lower receiver — it bolts to the back of the receiver with a single screw and changes how the rifle sits in your shooting hand. Brands stocked include Magpul (MOE, MIAD), B5 Systems P-Grip, Reptilia CQG, and budget polymer options. Most are direct drop-in fits for any mil-spec AR-15 or AR-10 lower.
Forward grips attach to your handguard or rail and give the support hand a positive index point. Vertical foregrips run perpendicular to the bore for a more traditional hold. Angled foregrips (AFG-style) lean the support hand into the gun for a thumb-forward C-clamp grip. Several models here combine a foregrip body with an integrated white-light flashlight, red laser, or green laser for one-handed activation while shooting.
Picatinny and M-LOK mounting are both represented — check the attachment method against your handguard or rail system before ordering. If you're spec'ing a full build, pair your grip with a buffer tube kit and a complete barrel and parts set. Free shipping on every order.
AR-15 lower parts kits and related components. A lower parts kit (LPK) contains everything below the upper receiver except the trigger group, stock, pistol grip, and lower receiver itself — fire control parts, springs, detents, takedown pins, bolt catch, magazine catch, and safety selector. Required for every AR-15 build.
Standard mil-spec LPKs (like the Spike's Tactical kit) use stamped-steel parts and are the right call for a budget build or a beater rifle. Enhanced kits (like Strike Industries Enhanced LPK) substitute machined or upgraded parts for the bolt catch, magazine release, and takedown pins — worth the extra spend if you want anti-walk pins or improved ergonomics.
The LPK is one of the last items you install on a stripped lower. See our sub-$400 AR-15 build list for a parts breakdown that puts the LPK in context, and our AR-15 accessories guide for upgrade priorities after the rifle is functional. Pair the LPK with a handguard sized to your barrel and gas system.
State laws on lower receivers and certain configurations vary. Verify local regulations before purchasing or building.
AR-15 muzzle devices — flash hiders, muzzle brakes, compensators, and blast shields. Most inventory is 1/2x28 for 5.56/.223 barrels; some 9mm and .308 options in 1/2x36 and 5/8x24. Pick by what you need the device to do: hide flash, reduce recoil, reduce muzzle rise, or some combination.
5.56/.223 AR-15 barrels use 1/2x28. AR-10 / .308 barrels use 5/8x24. AR-9 9mm barrels typically use 1/2x28 or 1/2x36 depending on the manufacturer — verify the stamp on your barrel before ordering. Thread pitch matters more than caliber: a 5.56 muzzle device will physically thread onto a 9mm 1/2x28 barrel, but the bore is undersized for 9mm projectiles. Use a 9mm-specific device for a 9mm carbine.
For more on AR muzzle setups see our handguard comparison (free-float handguards expose more of the muzzle device and matter for brake clearance) and our AR-15 accessories roundup.
Optics for your rifle — reflex and red dot sights, prism optics, and low-power variable scopes from Sightmark, Holosun, Trinity Force, and more. Whether you are setting up a close-quarters carbine, a duty rifle, or a precision build, find the magnification, reticle, and mounting footprint to match. Pair an optic with the right mount and finish the build with the rest of our AR-15 parts. Free shipping on every optic.
The detail parts that complete an AR-15 build — safety selectors, bolt catches, delta rings, dust covers, forward assists, and the small components that do not come in a kit. Whether you are finishing an upper, refreshing a lower, or replacing a worn part, find the piece you need. Browse charging handles, barrels, and all AR-15 parts. Free shipping store-wide.
The world of firearms is a realm of constant evolution, with enthusiasts and professionals alike seeking to optimize their shooting experience. Within this realm, a critical component that often garners attention is the AR trigger. AR triggers play a pivotal role in accuracy, control, and overall shooting satisfaction. In this comprehensive guide, we will delve into the intricacies of AR triggers, examining their importance, types, customization options, and the factors to consider when selecting the ideal trigger for your AR platform.
Find stripped and assembled AR-15 upper receivers from brands like Aero Precision, Spike's Tactical, BCM, and more. Whether you are building from scratch or upgrading an existing rifle, our selection includes mil-spec forged uppers, billet slick-side receivers, and complete assembled uppers with barrels and handguards pre-installed. All AR upper receivers ship with free shipping from Florida.
