Bolt Bounce

What Is Bolt Bounce?

Bolt bounce is an AR-15 malfunction where the bolt carrier group (BCG) rebounds off the buffer and returns forward before the magazine can present the next cartridge. This creates a condition where the bolt closes on an empty chamber, resulting in a failure to feed.

During normal operation, your AR-15’s bolt carrier travels rearward under gas pressure, compresses the buffer spring, then returns forward at a controlled rate. With bolt bounce, the carrier impacts the buffer with excessive force and immediately rebounds forward, outpacing the magazine’s ability to lift the next round into position.

Why Bolt Bounce Matters for Builders

Understanding bolt bounce helps you select compatible components when using the AR15 Outfitters builder. Three primary factors contribute to this malfunction:

• Overgassing: Excessive gas port pressure drives the BCG rearward too forcefully
• Light buffer weight: Standard carbine buffers (3.0 oz) may be too light for certain gas systems
• Weak buffer spring: Springs lose tension over time, reducing their ability to control BCG movement

Preventing Bolt Bounce in Your Build

To reduce bolt bounce in your AR-15 build, consider these solutions:

1. Increase buffer weight: Upgrade from a carbine buffer to an H1 (3.8 oz), H2 (4.7 oz), or H3 (5.6 oz) buffer. The additional weights inside help control BCG velocity.
2. Install an adjustable gas block: This allows you to tune gas pressure to match your buffer system and ammunition.
3. Replace the buffer spring: A fresh spring rated at 11-13 pounds typically provides optimal tension.

When selecting components, remember that heavier buffers generally reduce bolt bounce but may cause short stroking with low-pressure ammunition. Test your build with various ammunition types to ensure reliable cycling across different loads.