The M16A1 parts kit lower receiver assembly packages generally consist of the mentioned stripped lower receiver, buttstock, trigger, hammer, safety, pistol grip, buffer tube, recoil spring, and buffer. So, in states where such a purchase is not prohibited, many AR-platform builders will buy a lower receiver assembly. You need to understand clearly what their ruling is on the purchase of any firearms part. This makes it essential to check your local state laws. That being said, some state laws go against ATF policy and federal law by labeling firearm parts as firearms. The ATF refers to these “receiver blanks” and, as such, have decreed they are not defined as firearms. This is officially known as an “unfinished firearms’ receiver,” and they can be purchased without a Form 4473 or any other paperwork. However, it is possible to purchase an 80% lower receiver. The reason for this is because it is classed by the ATF (Bureau of Alcohol, Tobacco, and Firearms) as a controlled part. This has a slightly less complex build than the upper, but is potentially a more complex purchase!īuying a complete (100%) lower kit is subject to procedures that must be followed when purchasing a complete firearm. Moving down brings us to the lower receiver parts kit. It is also important that your handguard or forend are chosen to fit the gas system length of your barrel. It is important to match the correct gas system length because it will ensure smooth cycling and moderate recoil. When deciding on the barrel length you want, make sure it matches your chosen gas block and gas system. It goes without saying that your choice of barrel is an essential and personal part of your build.
Note on the delta ring: If you choose a handguard that is free floated, quad rail, or a proprietary handguard/rail system, your upper kit does not need to contain one. When looking at the best quality M16A1 parts kits for a complete upper, they should also include a gas tube, rear and front sight assembly, flash hider, and delta ring. Other equally key parts of an upper are the charging handle, forward assist, and ejection port cover. This additional weight can help your AR-platform build cycle more smoothly.īCGs include the carrier, bolt with extractor, and other essentials such as the gas key, firing pin, and cam pin. They are legal and come in a little longer and heavier than the semi-auto option. Don’t let the full-auto term put you off. You can choose between what is termed an M16 full-auto BCG or an AR-15 semi-auto BCG. Let’s take a look at each in turn: 2 BCG options These are the Bolt Carrier Group (BCG) and the barrel. The upper holds various components, including the “guts” of your M16A1 build. If this is your first self-build, the complete upper assembly option is seen as being an easier solution. Deciding on which option is for you comes down to either a stripped upper receiver or a complete upper assembly. These come in different configurations and include a variety of needed and optional parts.īefore taking a look at 7 of the best M16A1 parts kit choices, here are the key components of each receiver… The Upper ReceiverĬommonly called the “upper,” this is the section that holds and protects critical parts of the AR rifle. Anyone looking to build their own weapon will find a wide selection of both receivers available.
The tried and trusted design of an AR-15 comes from two main sections the upper receiver and the lower receiver. It’s all about the upper and lower receivers! PSA Upper Build Kit and Classic Lower Parts Kit Combination (Model No: 37448).But which of these Best M16A1 Parts Kits Should You Buy?.Looking for more Superb Accessories or Upgrades for your AR-15?.7 Double Star – ACE Essential Retro Aluminum CAR Buttstock Assembly – Best M16 Kit Buttstock Assembly.6 Brownells – Best M16 Kit Retro Pistol Grip.5 Brownells – AR-15/M16A1 Rifle Buffer Tube Assembly – Best M16 Kit Buffer Tube Assembly.