The guy on TN Outdoors youtube channel just tested the 102gr GS and got no expansion and an average of about 900fps with a bersa .380. His test was into 4 layers of denim and then ballistic gel. Interesting to see your results. Thanks for posting.
EDIT: just thought of something, why don't people test through a layer of cotton and a layer of rayon (common shirt material) rather than 4 layers of denim? I mean, have you ever seen a guy wear 4 jean jackets?