Five More AR Builder Mistakes

Published on April 10, 2024
Duration: 14:34

This video details five common AR-15 build mistakes. It covers accessory interference with the gas block, improper gas block alignment leading to cycling failures, incorrect castle nut torque (40 ft-lbs recommended), over-lapping the upper receiver during lapping, and incorrect buffer tube depth affecting the buffer detent. Addressing these prevents accuracy issues and ensures reliable function.

Quick Summary

The correct torque for an AR-15 castle nut is 40 ft-lbs. Overtorquing can damage receiver extension threads, while improper gas block alignment can cause cycling failures due to carbon buildup affecting the gas port.

Chapters

  1. 00:00Introduction: 5 More AR Builder Mistakes
  2. 00:42Mistake 1: Accessory Interference & Accuracy
  3. 03:42Mistake 2: Gas Block Alignment Issues
  4. 07:06Mistake 3: Castle Nut Torque Errors
  5. 08:49Mistake 4: Over-Lapping Upper Receiver
  6. 11:42Mistake 5: Buffer Tube Depth Problems

Frequently Asked Questions

What is the correct torque for an AR-15 castle nut?

The recommended torque for an AR-15 castle nut is 40 ft-lbs. Overtorquing can damage the receiver extension threads, while undertorquing can lead to a loose stock.

How can accessory mounting affect AR-15 accuracy?

If accessory mounting screws contact the barrel or gas block, they can interfere with barrel harmonics, negatively impacting accuracy. Ensure screws are short enough or accessories are positioned to avoid contact.

Why is proper gas block alignment crucial for an AR-15?

Improper gas block alignment, even slight, can cause cycling failures over time. Carbon buildup can obstruct the gas port if it's not perfectly centered, leading to malfunctions.

What happens if an AR-15 upper receiver is lapped too much?

Over-lapping an AR-15 upper receiver removes too much material. This can cause the barrel to sit too deep, leading to issues with feed ramp alignment and cam pin timing.

Related News

All News →

More Gunsmithing & DIY Videos You Might Like

More from Brownells, Inc.

View all →