Flapper-Locking Firearms

Published on December 18, 2012
Duration: 4:58

This expert guide from Forgotten Weapons delves into the mechanics of flapper-locking firearm systems. It details how flappers, attached to the bolt, engage with receiver recesses to lock the breech during firing. The explanation highlights the critical role of flapper size and engagement surface area in system safety and reliability, using examples like the DP-28 and contrasting them with the less successful G41.

Quick Summary

Flapper locking is a firearm operating system where two 'flappers' attached to the bolt engage with recesses in the receiver to lock the breech. This mechanism is activated as the bolt moves forward into battery, ensuring a secure lock before firing. Examples include the DP-28 and G41.

Chapters

  1. 00:14Introduction to Flapper Locking
  2. 00:27History and Development of Flapper Locking
  3. 00:43DP-28: A Flapper-Locking Example
  4. 00:50DP-28 Receiver and Flapper Mechanics
  5. 01:34Flapper Locking Engagement Demonstration
  6. 02:04Other Russian Flapper-Locking Firearms
  7. 02:22German Flapper-Locking Rifles: G41/G43
  8. 02:32DP-28 vs. G41 Flapper Comparison
  9. 03:33G41 Design Flaws and Dangers
  10. 04:00Risks of Small Flappers and Historical Failures

Frequently Asked Questions

What is flapper locking in firearms?

Flapper locking is a firearm operating system where two 'flappers' attached to the bolt engage with recesses in the receiver to lock the breech. This mechanism is activated as the bolt moves forward into battery, ensuring a secure lock before firing.

Which firearms use the flapper-locking system?

Notable firearms utilizing flapper locking include the Russian DP-28, DShK, and RPD light machine guns, as well as the German G41 and G43 semi-automatic rifles. The system's origins trace back to patents around 1870.

What are the advantages and disadvantages of flapper locking?

The DP-28's large flappers offered a robust lock. However, smaller flappers, as seen in the G41, can lead to less safety margin, potential for uneven load bearing, and issues with primary extraction, causing case failures.

How does the flapper locking mechanism engage?

As the bolt travels forward, a wedge, often part of the firing pin extension, pushes the flappers outward. These flappers then seat into angled recesses within the firearm's receiver, creating a locked breech for safe firing.

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