Fra Bergara 13/6-19:
"Basically, your 2017 bolt design don´t allow heavy loads, it work fine on factory ammunition, but not for reloaders. Summarizing a lot, the pin and hole are too large, we made an improvement last 2018 designing a thinner firing pin, so all Bergara SA rifles manufactured from mid-2018 are stronger. This allows heavier hand load on less cratering, because pin/hole surface on primer is smaller.
Unfortunately, there is no upgrade kit available, too complicate and dangerous to modify the bolt head without getting back the rifle to factory in Spain."