Good question. I don't know for sure, but I highly suspect that what they are talking about is the older, original 38Super brass, like from the 80's and earlier.
38Super was almost a forgotten cartridge, something Ian McCollum might be interested in. It had been on the books for 50 years and no police departments or sporting groups used it. It had been invented in the 1930's, supposedly as the next progression because designers recognized the power limitations of 38Special. But shortly after it's introduction the 38Super had itself been
totally eclipsed by the introduction of 357Magnum. So it languished.
Then, action pistol shooters picked it up as a "fix all" in the mid 1990's. Everyone was attracted to the 9mm Luger, but they simply couldn't get enough powder into the small cartridge. (357SIG and 40S&W were other "answers" to this same issue.)
With 38Super they could 1) easily pack more powder behind their 9mm-sized bullet, and then 2) shoot it in a 1911 with it's more robust barrel and frame. (Remember that 9mm in the 1911 hadn't been invented. The 1911 action at that time only accepted longer cartridges.) Super looked and loaded just like 9mm, but it was the Luger cartridge on steroids.
Only tiny design issues remained. The original design of the 38Super had the cartridge headspace on the rim, like a revolver. Action pistol shooters required an update, and so the new makers started headspacing the cartridge on the case mouth, as per the JMB inventions. When that happened, the diameter of the rim could be reduced to make the cartridges stack and feed more easily. Thus the introduction of 38SuperComp, 38SuperTJ, and others. Since the whole object was to shoot the new 38Super at much higher velocities, the designers of the new cases also took the liberty to strengthen the case head at the same time.
So there was originally (say about 1995) a marked difference between standard 38Super and 38SuperComp cartridge cases.
As we move into the 21st century what we find is that no one carries the 38Super in 1911 for self defense. If you're going to carry a 1911, it's going to be in 45ACP. And conversely, if you're
not going to carry a 1911, then it's going to be a mid-sized polymer gun in 9mm or 40, or an alloy sub-nose in 38Spcl +P. Therefore, almost the entire public for 38Super has some link to its modern competition heritage. As such, this crowd wants competition type performance in a civilian pistol. Therefore, looking at the cartridge from this vantage point it's easy to understand how
ALL 38Super cartridge cases are now coming with the strengthened case head.
That's my story and I'm sticking to it.
