19 of 19 Items
19 of 19 Items
Quality, U.S.-made AR-15 lower parts kits.
The lower parts kit - which contains your AR-15's hammer, trigger, safety, and disconnector - make or break the overall "feel" of your black rifle or pistol. A poorly machined trigger and hammer will make for a poor trigger pull. We only work with the country's best gunsmiths and manufacturers to provide quality, mil-spec AR lower parts kits for all your AR builds.
A complete lower parts kit includes the following components which are necessary to assemble any AR lower you fabricated with an 80% jig, or FFL-bought stripped lower receiver:
Need help? Follow our LPK install guide step by step.
Our guide covers every step in detail, with pictures. We cover how to install the hammer, trigger, safety, and all pins and springs, plus the other parts required to fully assemble your lower before installing your upper receiver.
Most lower parts kits do not include the buffer assembly, which is required for the upper receiver to operate and cycle rounds via the bolt and recoil spring. Grab a buffer tube or full buffer kit that include the recoil spring, buffer, castle nut before attempting your installation.
As shown in our install guide, we also strongly recommend investing in a set of roll pin punches and gunsmith hammer.
Thankfully, the AR-15's various calibers all utilize the same parts kits. Even .308-receiver builds, like the .308 Winchester and 6.5 Creedmoor, use mostly AR-15 components in the parts kits. We have a quality .308/AR-10 parts kit for those builds available here. Building anything like a 300 Blackout, 9mm (AR9), 6.5 Grendel or regular old 5.56/.223 gun? Grab a standard AR-15 parts kit! They all use the same LPKs and buffer assemblies.
The latch plate is the unit that retains the safety lever hardware with the buffer tube. It's also the perfect place for a quick-detach swivel sling mount. We've sourced some quality upgraded latch plates that provide multiple sling mounts and fold-out function for your buttstock and buffer, like the Sylvan Arms Folding Stock Adapter.
DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At GunBuilders.com, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.
We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.