In Berserk , the dragon-related berserk moment is generally seen after the Golden Age arc , beginning around chapter 95 when the story returns to the present timeline.

Context

  • The Reddit discussion says the present-day storyline starts after the ā€œHe Who Hunts Dragonsā€ chapter, with the Black Swordsman material happening before that, and places the transition at chapter 95.
  • That matches the common fan answer for when Gutsā€™s dragon-hunting, berserk-style present-day phase really shows up.

Quick note

If you meant the Dragon Slayer weapon rather than a ā€œdragon berserkā€ scene, the answer is still tied to the post-Golden Age present-day chapters, especially around chapter 95 onward.

TL;DR: Chapter 95 is the usual point fans point to for the start of the dragon-hunting present-day Berserk storyline.