18" Mountain Gun - My Old Standby [BUILD]

Published on June 24, 2020
Duration: 13:40

This video details a custom 18-inch AR-15 build, dubbed the 'Mountain Gun,' focusing on its role as a reliable, long-term firearm. The presenter explains the philosophy behind its configuration, emphasizing dependability over cutting-edge features. Key components discussed include a Rainier Arms pencil barrel for weight reduction, a Midwest Industries KMR-style handguard, an ACOG optic for its durability and nostalgia, and a Geissele SSA-E trigger for a crisp two-stage break. The build prioritizes a balance of weight, reliability, and familiarity for the user.

Quick Summary

This 18-inch AR-15 'Mountain Gun' build prioritizes reliability and familiarity, evolving from a DMR/SPR role to an 'old reliable' firearm. Key components include a lightweight Rainier Arms barrel, a Midwest Industries handguard, an ACOG optic for durability, and a Geissele SSA-E trigger. The presenter emphasizes not changing parts to maintain consistent zero and confidence in the setup.

Chapters

  1. 00:00Intro & Build Philosophy
  2. 03:39Lower Receiver Components
  3. 04:04Sling & Grip
  4. 04:47Lower Receiver Details
  5. 04:51Upper Receiver & BCG
  6. 05:01Charging Handle
  7. 05:29Optic: ACOG
  8. 05:78Barrel: Rainier Arms
  9. 06:20Handguard: Midwest Industries
  10. 06:67Muzzle Device: Dead Air
  11. 07:06Weight & Balance
  12. 07:21Weapon Light: Cloud Defensive Rein

Frequently Asked Questions

What is the primary philosophy behind the 18-inch 'Mountain Gun' build?

The primary philosophy is to create a reliable, 'old reliable' firearm that the user can always trust to be zeroed and configured correctly. This means avoiding frequent part swaps and prioritizing dependability over the latest trends or optimal configurations for specific roles.

What barrel and handguard are used on this 18-inch AR-15 build?

The rifle features an 18-inch Rainier Arms pencil-weight barrel for weight reduction and a Midwest Industries KMR-style handguard, known for being lightweight and ultra-thin, though it can flex under torque.

Why was an ACOG optic chosen for this rifle build?

The ACOG was selected for its proven durability, clear glass, wide field of view, and nostalgic appeal. It fits the rifle's theme and reliably performs for both long-range engagements and close-quarters scenarios.

What are the key considerations for the lower receiver components on this 'Mountain Gun'?

The lower uses a Stag Arms receiver for sentimental value. It intentionally omits an ambi-safety to prevent accidental engagement when the rifle is slung on the back, a practical consideration for a 'mountain gun'.

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