Smyth Busters: AR-10 vs AR-308 - What's the Difference?

Published on May 18, 2021
Duration: 5:25

This guide, presented by experts from Brownells, clarifies the critical differences between the ArmaLite AR-10 and the DPMS/LR-308 (AR-308) patterns. It highlights key distinctions in receiver cuts, handguard interfaces, internal components like bolts and gas tubes, and buffer systems. While many parts are not interchangeable, some components such as fire control groups and furniture are compatible. The information is crucial for builders to avoid compatibility issues and ensure proper assembly of .308 AR-style rifles.

Quick Summary

The main difference between AR-10 and AR-308 rifles is their design pattern. 'AR-10' refers to the original ArmaLite pattern, while most modern .308 AR-style rifles follow the DPMS/LR-308 pattern (AR-308). This affects critical parts like receiver cuts (straight for AR-10, curved for AR-308), bolts, gas tubes, and buffers, meaning most components are not interchangeable.

Chapters

  1. 00:00AR-10 Myth vs. Reality
  2. 00:45Parts Interchangeability Issues
  3. 01:15Receiver Geometry Differences
  4. 01:40Handguards and Rail Heights
  5. 02:08Bolts, Barrels, and Gas Tubes
  6. 02:30Buffer System Variations
  7. 02:52Interchangeable Components
  8. 03:20Magazine Compatibility Explained
  9. 04:20Conclusion & Naming Conventions

Frequently Asked Questions

What is the main difference between an AR-10 and an AR-308 rifle?

The primary difference lies in their design patterns. 'AR-10' specifically refers to the original ArmaLite pattern, while most modern .308 AR-style rifles follow the DPMS/LR-308 pattern, often referred to as AR-308. This distinction affects critical components like receiver geometry and parts compatibility.

Are AR-10 and AR-308 parts interchangeable?

No, most critical parts are not interchangeable. Key differences include receiver cuts (straight for AR-10, curved for AR-308), bolts, barrel extensions, gas tubes, and buffer systems. While some components like triggers and furniture may be compatible, direct swapping of major parts will likely lead to function issues.

How can I identify the difference between an AR-10 and an AR-308 receiver?

The easiest way to differentiate is by looking at the rear of the upper receiver. An original ArmaLite AR-10 pattern will have a straight cut at the back where it meets the lower receiver. In contrast, the DPMS/LR-308 (AR-308) pattern features a distinct curved cut at the rear.

What parts are generally compatible between AR-10 and AR-308 platforms?

While many core components differ, several parts are typically interchangeable between AR-10 and AR-308 platforms. These include the fire control group (trigger and hammer), pistol grips, buttstocks, and muzzle devices. Always verify compatibility with specific manufacturers before purchasing.

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