I've heard that this round was developed specifically for the .380acp (Ruger LCP) and that it penetrates and expands reliably in that caliber. I have a few boxes on backorder and am looking forward to trying them out.
They fire flawlessly thru my P3AT, and I'll try them thru my LCP on my next trip to the range. Hornady appears to have hit a home run with these SD rounds.