What your shoots best could depend on barrel twist to a point. 120gr NBT is a tougher light weight bullet that tends to shoot well. A small powder weight change can make a big difference in how well it shoots . If your useing a older mauser miltary rifle it may need a heavier bullet to be more accurate.
I have only shot a few bullets in my 7rem mag. 1-9.5 twist barrel. 139gr sst 140gr NBT or NAT are very accurate. The 139gr sst has been my deer round for 12 years. But I have handloaded 168 gr hpbt match kings. That would group half the size of the 140 class bullets.