14mm Emplacement Turret kills with recoil

The 14mm turret (turret_bullets2) will kill you if you stand behind it and fire it in one hit. Standing off to the side will band aid fix the issue but I don't recall this being an issue in the past.

Start by locating the turret_bullets2 implementation and reproduce the 14mm emplacement behavior by firing while standing behind it. Trace how recoil or damage reaches the operator, then verify in-game that firing from behind no longer kills the operator while the turret continues to function.

Written by the indexing model from the issue text.