Have your handloads ever shot acceptable groups? I ask because maybe (if you only shot good groups with the S&B ammo at first) you are shooting S&B ammo from a different lot number and there are small changes in the different lot of ammo causing the difference.

If I were you I would send it to JJ at Champlins for a check up. If all is ok I would either work up a load that shoots to regulation myself or if for some reason wasn't able to would have Champlins do the load development. I have heard that Superior Ammunition also does load work for DR's but don't know how good or bad they are at it.

Good Luck.

Out of curiosity... To the othe Chapuis 9.3 owners on the board, How accurate was your rifle out of the box? Were the barrels crossing at 100yds?