AR-15 Build Kits
Frequently Asked Questions about AR-15 Build Kits?
- What is an AR-15 Build Kit?
An AR-15 Build Kit provides nearly everything you need to assemble an AR-15, excluding the lower receiver (legally considered the firearm). Typically, these kits contain a complete upper receiver (assembled or unassembled), a lower parts kit (LPK), and a buffer tube assembly, which may include the buffer spring, buffer weight, and stock. With a build kit, enthusiasts can customize their rifles to their specific needs while assembling them from the ground up, providing a hands-on learning experience that can be more cost-effective and tailored than purchasing a complete firearm. - Why doesn’t the AR-15 Build Kit come with a lower receiver?
The lower receiver is classified as the serialized firearm component under U.S. federal law. It is subject to stricter regulations than other rifle parts and must be purchased through a Federal Firearms License (FFL) holder. This means that a background check, by state and federal laws, is typically required for purchase. By excluding the lower receiver, build kits allow individuals to acquire the remaining parts without going through the same regulatory process as buying a complete firearm. - Is an AR-15 Build Kit compatible with all AR-15 lower receivers?
Most AR-15 Build Kits are designed to be compatible with mil-spec (military specification) lower receivers, which form the industry standard. As long as your lower receiver is mil-spec, you can typically expect it to be compatible with the parts in the kit. However, some lowers have proprietary features or unique dimensions, such as certain billet lowers or those with enhanced trigger guards. It’s always recommended that compatibility with your specific lower receiver be confirmed to avoid fitment issues. - Do I need special tools to assemble an AR-15 Build Kit?
While assembly can be done with basic hand tools, certain specialized tools can make the process easier and more precise. Tools commonly used for assembling an AR-15 Build Kit include: -
- Armorer’s Wrench: This multi-purpose tool tightens barrel nuts, castle nuts, and other components.
- Punch Set and Hammer: These are used for installing small pins, such as the roll pins used to secure the trigger guard or bolt catch.
- Vise and Vise Blocks: Secure the upper and lower receiver during assembly.
- Torque Wrench: Ensures components like the barrel nut are tightened to the correct torque specification.
- While not necessary for all steps, these tools can prevent damage to parts and ensure everything is assembled correctly and safely.
- What types of calibers are available for AR-15 Build Kits?
While 5.56/.223 Remington remains the most popular caliber for AR-15 Build Kits due to its widespread availability, compatibility, and versatility; many kits also come in other calibers. Options include .300 Blackout (ideal for suppressed shooting), 7.62x39mm (similar ballistics to the AK-47 round), 6.5 Grendel (for longer-range precision shooting), and .224 Valkyrie (known for flatter trajectories). Choosing a caliber depends on your intended use for the rifle, whether it’s home defense, hunting, target shooting, or long-range competition. - Are AR-15 Build Kits easy to assemble for beginners?
Many people find assembling an AR-15 Build Kit to be an accessible and rewarding project. Beginners can follow detailed video guides, step-by-step instructions, or even online tutorials from experienced builders. While the process requires attention to detail, patience, and mechanical skill, it doesn’t require specialized gunsmithing expertise. Beginners should take their time, verify each step, and, if in doubt, seek advice from experienced builders or professional gunsmiths. - Do AR-15 Build Kits include sights or optics?
In most cases, AR-15 Build Kits do not include sights, optics, or other accessories like red dots or magnified scopes. This omission allows builders to select optics that best suit their intended use, whether close-quarters shooting with a red dot sight or long-range precision shooting with a magnified optic. Budgeting for optics is important, as quality sights can significantly enhance your rifle’s performance. - Is there any fitting required when using an AR-15 Build Kit?
Generally, AR-15 Build Kits are manufactured to fit together with little to no fitting required. Most parts adhere to mil-spec standards, ensuring a consistent fit. That said, minor fitting may occasionally be needed due to slight manufacturing variations. Builders might initially encounter tight-fitting parts; this can often be addressed by properly seating parts or using a small amount of lubrication. If a part refuses to fit, double-check its compatibility and consider contacting the manufacturer for guidance. - Are there legal restrictions on building an AR-15 from a Build Kit?
In the United States, it is typically legal to build an AR-15 for personal use as long as the builder complies with federal, state, and local regulations. This may involve ensuring compliance with laws regarding barrel length, banned features (such as pistol grips or adjustable stocks in some states), and registration requirements in certain areas. Federal law prohibits the sale of a personally built firearm unless the builder has the proper licenses. Always research and understand the laws in your jurisdiction before beginning any firearm build. - How do I know if an AR-15 Build Kit is good quality?
High-quality AR-15 Build Kits often feature parts made from top-grade materials, such as 7075-T6 aluminum for receivers and 4150 CMV (Chrome Moly Vanadium) steel for barrels. Reputable brands often provide better quality control, durability, and customer support. When selecting a kit, look for user reviews, manufacturer reputation, and warranties. Trusted manufacturers like Aero Precision are often favored for their consistency and high-quality components. Testing and quality assurance measures, such as magnetic particle inspection (MPI) of critical components like bolt carrier groups, can also indicate a higher-grade product.
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16" AR15 5.56 Standard Rifle Build Kit W/15" M-LOK Handguard
Black Rifle Depot
$499.9516" 5.56 Standard Rifle Build Kit W/15" M-Lok Handguard The perfect AR 15 rifle build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 rifle build kits are made from the highest quality USA produced...$499.95 -
10.5" 5.56 Premium AR 15 Pistol Build Kit W/ M-LOK Handguard
Black Rifle Depot
MSRP: $599.95$529.9510.5" 5.56 Premium AR 15 Pistol Build Kit W/9.85" M-Lok Handguard The perfect AR 15 pistol build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 pistol build kits are made from the highest quality USA...MSRP: $599.95$529.95 -
16" 5.56 Standard Carbine Rifle Build Kit W/13" M-LOK Handguard
Black Rifle Depot
$679.9516" 5.56 Standard Carbine Rifle Build Kit W/13" M-Lok Handguard The perfect AR 15 build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 rifle build kits are made from the highest quality USA produced...$679.95 -
16" 5.56 Premium Rifle Build Kit W/15" M-LOK Handguard
Black Rifle Depot
MSRP: $699.95$579.95Patriot 16" 5.56 Premium Rifle Build Kit W/15" M-Lok Handguard The Patriot 16" 5.56 Premium AR 15 Rifle Build Kit is the ultimate choice for anyone looking to build an AR 15 rifle from scratch. This build kit includes all the components...MSRP: $699.95$579.95 -
18" AR 15 .223 Wylde Rifle Build Kit
Black Rifle Depot
$599.95Black Rifle Depot 18" AR 15 Rifle Complete Build Kit includes everything you need to finish your stripped lower receiver. This kit includes our 18" .223 Wylde Upper Assembly with Toolcraft, Inc. Black Nitride Bolt Carrier group. Plus...$599.95 -
16" 5.56 Premium Rifle Build Kit W/13" M-Lok Handguard
Black Rifle Depot
Now: $529.95Was: $679.9516" 5.56 Premium Rifle Build Kit W/13" M-Lok Handguard The perfect AR 15 rifle build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 rifle build kits are made from the highest quality USA...Now: $529.95Was: $679.95 -
11.5" 5.56 Premium AR 15 Pistol Build Kit W/9.85" M-LOK Handguard
Black Rifle Depot
$549.9511.5" 5.56 Premium AR 15 Pistol Build Kit W/9.85" M-Lok Handguard The perfect AR 15 pistol build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 pistol build kits are made from the highest quality USA...$549.95 -
16" AR 15 Complete Rifle Kit with 15" M-Lok Handguard
Black Rifle Depot
$599.9516" 5.56 NATO AR 15 Complete Rifle Kit with 15" M-lok Handguard This 16" 5.56 NATO AR 15 Complete Rifle Kit with 15" M-Lok Handguard comes with everything need to finish your AR 15 lower receiver. It is American made and assembled in the...$599.95 -
16" 5.56 NATO Cold Hammer Forged Rifle Build Kit
Black Rifle Depot
$769.9516" 5.56 NATO Cold Hammer Forged Rifle Build Kit The 16" 5.56 NATO Cold Hammer Forged Rifle Build Kit comes with the 16" Cold Hammer Forged Upper complete with M16 Black Nitride Bolt Carrier group and Mil-Spec charging handle. Also include is our...$769.95 -
16" AR-15 Complete Rifle Build Kit
Black Rifle Depot
MSRP: $654.95$429.9516" AR-15 Complete Rifle Build KitMSRP: $654.95$429.95 -
16" 5.56 NATO Super Slim AR-15 Rifle Kit
Black Rifle Depot
MSRP: $599.70$479.9516" 5.56 NATO Super Slim AR-15 Rifle Kit The Black Rifle Depot 16" 5.56 NATO Super Slim Rifle kit is built with a 16" 5.56 M4 profile 1:7 twist Mid-length gas system and an extended A2 Flash Hider. It's covered by 15" Ultra Light "super Slim" M-lok...MSRP: $599.70$479.95 -
Dirty Bird 16″ 5.56 NATO Govt M-LOK V3 Rifle Kit
Dirty Bird Industries
MSRP: $574.95$499.95Dirty Bird 16″ 5.56 NATO Govt M-LOK V3 Rifle Kit ThisDirty Bird 16″ 5.56 NATO Govt M-LOK V3 Rifle Kit features a Black Nitride 16″ Sub-MOA Government Profile barrel chambered in 5.56 with a 1:7 twist. Built on a top-tier Forged Upper...MSRP: $574.95$499.95 -
16" 5.56 Standard Rifle Build Kit W/12" M-LOK Handguard
Black Rifle Depot
MSRP: $675.74$479.9516" 5.56 Standard Rifle Build Kit W/12" M-Lok Handguard The 16" 5.56 Standard AR 15 Rifle Build Kit with 12" M-Lok Handguard from Black Rifle Depot is the ultimate solution for those seeking a high-quality, complete AR 15 rifle build kit. This...MSRP: $675.74$479.95 -
7.5" AR-15 Complete Pistol Build Kit
Black Rifle Depot
MSRP: $559.95$399.957.5" AR-15 Complete Pistol Build Kit - Disassembled Introducing the 7.5" AR 15 Complete Pistol Build Kit – a comprehensive set for enthusiasts and builders alike. This kit's heart is the 7.5" 5.56 NATO Barrel, optimized for precision and...MSRP: $559.95$399.95 -
7.5" Slick Side Billet AR-15 Pistol Kit
Black Rifle Depot
MSRP: $469.95$409.957.5" Slick Side Billet AR-15 Pistol Kit The 7.5" Slick Side Billet AR-15 Pistol Kit offers AR enthusiasts an affordable yet high-quality upper assembly. This kit features a 7.5-inch nitride-treated barrel chambered in 5.56 NATO, ensuring durability and...MSRP: $469.95$409.95 -
AR 15 Rifle Build Kit with 20" Barrel
Black Rifle Depot
$799.95AR 15 Rifle Build Kit with 20" Barrel This AR 15 Rifle Build Kit comes with everything you need to finish your AR 15 or variant lower receiver. The kit includes a complete 20" AR 15 Upper with a A2 front sight post and carry handle with rear sight. Also...$799.95 -
16" 5.56 AR-15 Rifle Build Kit W/12" Quad Handguard
Dirty Bird Industries
MSRP: $584.95$519.95Dirty Bird 16" 5.56 AR 15 Rifle Build Kit W/12" Quad Handguard The perfect AR 15 rifle build kit for your lower, without all the tools required to build it. Black Rifle Depot's complete AR 15 rifle build kit with quad handguard is made from...MSRP: $584.95$519.95 -
7.5" 5.56 NATO AR-15 Pistol Kit
Black Rifle Depot
MSRP: $489.95$419.957.5" 5.56 NATO AR 15 Pistol Kit The 7.5" 5.56 NATO AR 15 Pistol Kit comes with everything need to finish your AR 15 lower receiver. This kit includes a complete 7.5" 5.56 NATO Pistol upper with Black Nitride M16 Bolt Carrier Group and mil-spec charging...MSRP: $489.95$419.95 -
Aero Precision 11.5" 5.56 M4E1 Threaded Pistol Build Kit
Aero Precision
MSRP: $830.00$779.95Aero Precision 11.5" 5.56 M4E1 Threaded Pistol Build Kit The Aero Precision 11.5" 5.56 M4E1 Threaded Pistol Build Kit is the pinnacle of design and functionality, combining top-tier components suited for enthusiasts seeking superior performance and...MSRP: $830.00$779.95 -
Aero Precision 16" AR-15 Rifle Build Kit - Pinned FSB
Aero Precision
MSRP: $689.95$629.95Aero Precision 16" AR-15 Rifle Build Kit - Pinned FSB The Aero Precision 16" AR-15 Rifle Build Kit is a complete assembly package designed for precision and reliability. This kit features the Aero Precision 5.56 Carbine Upper Assembly, which includes a...MSRP: $689.95$629.95 -
10.5" 5.56 NATO AR-15 Pistol Kit
Black Rifle Depot
MSRP: $589.79$469.9510.5" 5.56 NATO AR-15 Pistol Kit The 10.5" 5.56 NATO AR 15 Pistol Kit comes with everything need to finish your AR 15 lower receiver. This kit includes a complete 10.5" 5.56 NATO Pistol upper with Black Nitride M16 Bolt Carrier Group and mil-spec...MSRP: $589.79$469.95