If you're new to purchasing firearms or lower receivers online, the process might seem a bit overwhelming. At Aerospace Arms, we're here to make it as simple and straightforward as possible. Below, we've outlined a step-by-step guide to help you successfully order your firearm or lower receiver a …

AR-15 Parts List: Complete Build Checklist and Compatibility Guide Last reviewed: October 2026 • Author: Andrew Maas In this guide: Introduction AR-15 Build Checklist Compatibility at a Glance Build Considerations Lower Receiver Parts Upper Receiver Parts Choosing a Barrel Bolt Carrier Group …

As most of us know, the most common questions tossed around in the AR community when building custom AR-15s are, “How do I build the lightest AR-15 possible?” or “What’s the best ultra-lightweight AR-15?” or “Where can I find the lightest AR-15 parts?” or some version of this question.  Who …