I was told by a forum member on here that the cartridge that looks larger will always be more powerful and a better choice obviously in that theory 38 special should be at least 1.5x the power of 9

In all reality I will always choose 9mm over 38 unless I feel the need to put some mileage back on a revolver.

Federal HST puts 13-17" of penetration with amazing expansion in 9mm even with shorter barrels where 38 special seems to be a struggle to find a loading that has adequate penetration and consistent reliable expansion in a short barrel.

Don't get me wrong I am a fan of both