Never mount the trigger at the rear end of the bolt. The firing pin must be overtensioned to close the bolt . If the trigger is mounted too far forward, the impact energy will not be sufficient, resulting in misses.
When cocked, measure the length of the signal pin that protrudes from the rear end of the firing pin. When you close the bolt, the indicator pin must protrude as far as before, this is then the correct position for the trigger. If you now operate the safety catch, you will notice that the catch bolt is lifted by the sear engagement .