The issue with 209's is that they say they are so powerful that they start movement of the round before ignition of the charge. This in turn they say leads to inconsistent groups. I personally have not found this to be the case or if it is it is so small that the average to even above average shooter will not notice it at all. I could see an issue if you are a match grade shooter but other than that it is industry hype. By the way I shoot modern ML's a lot.