I've seen in print that the 375 H&H magnum shoots bullets of different weights to about the same place.  In my experience with 270 and 300 grain bullets it seems to be true but there is only a 30 grain weight difference between them.  I also heard this recently about the 416 Rigby from a PH.
Has this been the experience of others?  Is there a logical explanation for this?  Are there other cartridges blessed with this characteristic?