Are we saying that the CD round will not penetrate barriers? Or that Hornady will not guarantee expansion once the bullet has penetrated barriers (other than clothing)?
I have a hard time believing the former. And as for the latter - so what? If you shoot a CD round through glass and it fails to expand...it will act like FMJ. LOTS of folks have been killed by FMJ.
The CD round was made to have low flash, low recoil (they're not +P in 9mm), reliable feeding, and reliable expansion through clothing. The trade-off is reduced performance through barriers. For CCW needs, that probably IS a good trade-off.
I alternate the .380 CD round with FMJ-FP in my LCP. The CD round gets ~ 11 inches in gel, just short of the FBI minimum...but it expands reliably, which cannot be said of many JHPs in .380. The FMJ gets 16-17 inches, which exceeds the FBI desired 15. This works for me.
Anyway, I think the benefits of JHPs are over stated. In handgun ammo, the main benefit of JHPs is reduced risk of overpenetration. I do not think JHPs are markedly better than FMJ in stopping a threat. Shot placement, and penetration to the vitals is it. Arguing about this bullet or that bullet is almost pointless. Kinda like the endless caliber wars.
Here's some tests including the CD round in 9mm:
And in .380:
Looks OK to me...but I'm not expecting magic either...