TheHunter: Call of the Wild Wiki

"A heavy weight broadhead bolt compatible with all types of crossbows.
The weight of an arrow, combined with the power of a bow, affect trajectory and penetration upon impact. A higher weight means more penetration at the cost of a less flat trajectory, making it harder to reliably hit a target.
― In-Game Description

The 600 gr. Broadhead Bolt is an ammunition type available for the Crosspoint CB-165 crossbow.

This ammo is available as part of the Weapon Pack 1 DLC.
The tracer variant is available as part of the High-Tech Hunting Pack DLC.