The season heavily utilizes symbolism to emphasize its tragic nature:

Season 6 begins with Jax Teller attempting to fulfill his father’s vision of moving the club away from the illegal gun business . However, this goal is immediately compromised by a horrific school shooting involving a KG-9 gun linked to the club—a plot point that forces the characters and the audience to confront the real-world consequences of their lifestyle .

The Sons of Anarchy's Mayhem Index: Season 6, Episode 5 | GQ