Model12 - if you have any of the brass around, could you possible measure and post the casing overall length of these "shorts". To me, they look like a 38 Colt Short "re-packaged" for a new and different "generation" of people.
I loas a lot of the Colt Shorts - the slug she show is very similar to a Lyman/Ideal 121 gr RN from a 358-242 mold. I'm guessing that the slug they are using is one with one lube groove and a thinner upper roll crimp groove.
I wish they would show some specs on these "shorts" but I couldn't find any when I looked.
I use three different cast bullets when loading the 38 Colt Shorts - the Lee 105 gr. SWC, a 115 gr Lead SWC out of an old Ideal .360 mold originally designed for the 38 S & W cartridge (not S & W "special") and the 121 gr RN 358-242.
The original 38 Colt Short was a black powder cartridge with a "heeled" bullet - designed for the 1851 Colt conversions (such as Richards & Mason).
I'm not "high tech" and I don't have a chronograph. I can't speak for the "38 Special Shorts" but from my own experience with my re-loads in the 38 Colt Shorts - they would do some damage as SD ranges. Poo poo if you will . . . but I don't think anyone would volunteer to stand at SD range and be shot with one.
I use them for plinking and yes, they are on the milder side but still nothing to sneeze at. Again, I don't have a chronograph but I would hazard a guess that the ballistics would be similar to a .380 ACP - give or take.