[Socrates]

Thanks for the FBI link! Lost it when my hard drive crashed.

From the above article:

Conclusions

Staring at the different views of the data - primarily sorted by bare and clothed wound volume - made me notice a few things, some obvious, some not:

1. terminal performance can be a lot different for a round in bare vs. clothed gelatin,
2. small, fast rounds that depend on lots of expansion to get wound volume (or width) can often be foiled by clothing (e.g.: .40 CCI/Speer GD 155gr: bare, it expanded by 110%, to 0.84, but in clothed gelatin, it only expanded by 54%),
3. bullets that start out smaller must expand to a larger percentage of their original size than a larger bullet to attain the same wound width,
4. less massy bullets have less "material" to work with in terms of expansion - they are stretched "more thin",
5. heavier, slower rounds in .40 (or 10mm) and .45 did extremely well in bare gelatin wound volume, but they ruled clothed gelatin wound volume. Their slow velocity did not prevent expansion. e.g.: the 230gr Rem Golden Saber .45 ACP at 871 fps expanded 58% in bare, and 62% in clothed gelatin!
6. the best 9mm rounds tested, according to wound volume in both cases, are the: CCI/Speer Gold Dot 124 +P, and the 147gr Black Talon. This made me re-evaluate my "carry" choice in 9mm, since it was a Proload/GD 115+P. I switched to 124+P.
7. the best .45ACP loads and the best .40 loads were pretty close. "heavy" 9mm's were noticably behind. "light" 9mm's were last,
8. while some 9mm 115's did well relative to the 124gr's and 147gr's in bare gelatin, they scored the worst in clothed gelatin,
9. 357SIG performs similarly to CCI/Speer GD 124 +P. The extra 100 fps didn't help much, either in penetration or wound volume.
10. pick a caliber you like, and then research the best bullet for your platform, since the particular load makes a much bigger difference than caliber in some cases (e.g.: a 9mm beating a .45),
11. stated another way, there are some general trends in terms of wound volume by caliber, but there is significant overlap based on particular load performance,
12. if a round fails to expand "normally" from clothing, there is a good chance it will over-penetrate.. sort by "(clothed gelatin) penetration depth" and notice how many are over 20" penetration,

The big caveat in these conclusions is that they are just one data point per load, and most of the data is pretty old. I wonder if some new loads would perform differently - e.g. would a 357SIG at 1450 FPS perform much better than this one at 1372fps?

As for Double Taps testing setup:

All of these tests were done using 10% ballistic gelatin provided by Vyse gelatin using all FBI protocols and 4 layers of denim and two layers of light cotton T-shirt in front of the gelatin.