The triggers need replacing and they are no longer available. I heard to fix the problem is a $500+ operation. I changed mine out years ago. The twist rate is slower on most calibers than now. Mine won't hadle anything over 130 lead bullets.
You are correct sir. I still have a frist Gen German Mark V in 300WBY. Has the old style trigger, tang safety, still works, but it has been retired. It's a 24" barrel, 12 twist, but shot 180 grns with IMR4350 in less than half inch.
To replace the trigger, the also need to convert the bolt to have the safey on the bolt. That's why it is so expensive. Keeping mine orginal, have replaced it with modern version.