We've tested a similar design in 9mm 3.5" to 16" barrels and yes, they do expand like the picture w/o significantly reducing penetration. Accuracy testing was inconclusive and quite variable gun to gun.
Based on the performance of similar bullets used in a 300BO sub-sonic, this is a very effective bullet. Petals will break off now and then but generally, bullets are found intact or missing 1 petal.
Would I carry them? 50/50, yes/no. Since I also haul a 300BO PDW in my work vehicle, I have more need for immediate, close range performance and accuracy beyond 15-20 yards of my carry gun is less of an issue.
Bottom line: Excellent terminal performance. If your personal gun functions well enough and you're satisfied with the accuracy, no reason not to use them.
