You will need to do a search, but I tested various .22 lr. from a 2" NAA Black Widow into Perma-Gel. The results are, I think in the the "North American Arms, much meaner than I thought" thread in the CCW forum, or the "Perma-Gel test results" thread in the ammunition forum. IIRC CCI Stingers gave the best performance. As I remember, I got about 13" penetration from the Stingers, with or without heavy clothing.