I had a Kel-Tec 32.
Federal HS 65 gr. @ 804 F.P.S. = 93# KE
Federal HS 90 gr. @ 845 F.P.S. = 143# KE
Based on my actual chrono results from comparable pistols using very comparable ammo, we could make a generalization and say the 380 is about 50% more powerful when compared "apples to apples".
Given that the 380 is really a marginal defensive caliber I would not want to rely on something with approximately 50% less power, especially when offered in about the same size package.