Try this; MidwayUSA lists the the Muzzle Velocity, and the Muzzle Energy levels for most of the loads that the sell. They list 2, 158 gr Fiocchi loads for 38 Special, one at M.E. of 295 ftlbs, the other @ M.E. 320 ft lbs. Compare your loading to the other 38 Special loads.
This is by no means the difinitive answer, but you'll get an idea of how much hotter they are. And yes they are a little more 'stout' than the other loads that I checked. Have your gunsmith check the gun to ensure that it is in good condition before you shoot them. A heavier load will put more strain on you, the gun, and of course the target.
I would find a lighter load for practice, and use them for p.d. use only.