Andrew from Vuurwapen Blog has created this slow motion video demonstrating AR-15 bolt carrier bounce. It shows how lighter weight buffers allow the bolt carrier to bounce back after hitting the barrel extension.

The weight of the buffer becomes critical when said items begin to reach the end of their lifespan (or were never satisfactory to begin with), or when the weapon has been fired for thousands of rounds without any lubrication, or when various types of ammunition are used.

I highly recommend reading Andrew’s blog post.

[ Many thanks to jdun1911 for emailing me the link. ]