I don’t really know, but I’ve gotten so attached to the 38 Super over the years. It’s a somewhat difficult cartridge to hand load. Its supposed to take a .356 bullet; but people have used .355 and .357 bullets in it. The biggest problem with the 38 Super is bullet setback in hand loads. Neck tension has to be tight. The bullet hits the feed ramp with considerable force. The can force the bullet back into the case and create very high pressures and a case head blow out.
My own 38 Super Colt Model 1911 started out as an ugly well worn project gun. With a trashed barrel, poor refinish and buggered trigger, it appeared beyond hope. It’s serial number placed production in 1958. However, the slide and frame and internals were in good shape, well worth the bargain basement price.
A set of Millet sights, Bar-Sto barrel and bushing, new trigger and parkerized finish put this gun right. The interest of the 38 Super is that it started live as the mild mannered 38 Automatic Colt Pistol cartridge in the elderly colt Model 1902 Pistol. Loaded to +P pressures in 1929 and chambered in the reliable and strong Model 1911 the super should have been an instant winner. It was not. The head spacing on the tiny cartridge rim ruined the accuracy potential of the cartridge. Its power was soon eclipsed by the much more powerful 357 Magnum in 1935.
For decades the 38 Super was a minor player; an unpopular second chambering in the popular model 1911.
In the 1980s the 38 Super was rediscovered action shooters, it could be hot loaded with fully supported barrels, to make the “major” power factor. New barrels that head spaced on the case mouth and solved the accuracy problems of earlier barrels. Since then, action pistol has moved on to 40 caliber guns. The 38 Super is now a modestly popular cartridge with a few enthusiasts. Personally, I think it’s great!!