I have a Speer LE poster they put out a year or two ago, comparing the various calibers penetration results in each of the FBI test categories and they show the 38 135+P out of a SW640 as having a velocity of 860 fps while the 125gr 357 Mag out of a M65 (no bbl length) is clocked at 1189 - presuming the 65 is a 3" I don't see how they claim 1450 from a 4".