A lower parts kit (LPK) is a collection of all the small parts typically needed to assemble the lower receiver of an AR-15 rifle. This usually includes the trigger assembly, sear, hammer, disconnector, bolt catch, magazine release, takedown pins, and springs. Some LPKs also include a grip and trigger guard – although these are often sold separately.
Installing an LPK is generally one of the first steps in building an AR-15 from scratch. It’s also a good way to replace worn or damaged parts on an existing rifle. Many gunsmiths and gun shops offer LPK installation services.
Choosing the right LPK can be tricky, as there are many different brands and variations available. It’s important to select a kit that is compatible with the specific make and model of your AR-15. You should also consider whether you want a “mil-spec” or “commercial spec” LPK. Mil-spec parts are designed to meet the rigorous standards of the U.S. Military, while commercial-spec parts are designed for the civilian market.
Mil-spec LPKs are often seen as the gold standard, as they are built to withstand the harshest conditions. However, they can be more expensive than commercial spec kits. Additionally, many shooters find that commercial spec parts work just as well – if not better – for their needs.
No matter which type of LPK you choose, be sure to do your research and select a kit from a reputable manufacturer. This will help ensure that you get a quality product that will last for years to come.
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