I was intrigued by this new .380acp offering from Fiocchi, a 90g. HP topped by the Hornady XTP bullet. I prepared my wetpack as usual, in this case, supersaturated with water for about 10 hours. I shot 3 rounds of the Fiocchi into the wetpack from a distance of about 10 feet. For comparison, I also shot a couple rounds of the highly regarded Corbon DPX, and the new Doubletap Gold Dot HP. Here are the expansion/penetration results. Remember that penetration in wetpack is approximately 2/3 of what it would be in ballistic gelatin. 1. Fiocchi: Penetration: 6.5-6.75". Expansion: .45" 2. Corbon DPX: Penet.: 5.5-6.0". Exp: .68" 3. Doubletap Gold Dot: Penet: 5.5-5.75". Exp: .52" Clearly, the Hornady XTP bullet has minimal expansion out of the short-barreled P3AT, getting a bit more penetration with its near-FMJ profile. This test is consistent with other tests I've seen, where the Hornady XTP bullet shows some failings as an expander. The Corbon DPX still shows the premier expansion in .380acp HP ammo, as well as excellent (for this caliber) penetration. The Doubletap Gold Dot is an outstanding alternative, with its proven Speer bullet, and does well in both test criteria. It's cost ($24 for 50) compared to the DPX (over $20 for 20) makes it especially appealing.