Here's a nice comparison of several different calibers and bullet weights. As you can see the 147 gr. 9mm has the deepest penetration of all the rounds tested.
I don't see how he could say it's significantly worse than the lighter 9mm rounds. I'd have to hear his reasoning. I practice and worry more about shot placement than some "expert's" opinion that a 147gr. 9mm won't stop someone.
I bought some Federal 9mm 147gr HS rounds from Ammunition To Go, at a really good price I might add.
I was looking forward to sending some rounds downrange from my Kahr CW9. At 7 yds, performance was good and I kept a pretty good grouping (good for me, anyway). I was also shooting my RIA compact .45 with regular 230 FMJ. I moved the target out to 10 yds and the .45 was fine, but with the 9mm I could hardly keep the rounds on the paper. Not sure where they were going, but not on the target! I don't usually have this kind of trouble with the 9mm. I was switching back and forth between the two guns and the .45 was right on target but the 9mm was outta there
I have used 124gr HP rounds without problems, but the 147gr was very disappointing. I'll go back to 124 and sacrifice a bit of punch for more control.