Ramslammer: the 38/45 was developed by Ed Clarke in Louisana better than 30 years ago. It is a 45 acp case necked down to take the 38 special wadcutter bullet. The cartridge was designed for mid-range accuracy shooting for those who didn't want to get another pistol for target matches when they used the 22lr, 38 spl and 45acp as the 3 different calibers. This cartridge allowed for a quick barrel change from 45 acp to the 38/45 so the shooter could use the same pistol (grip, sights, trigger, etc) and not have to go to a different pistol/revolver to shoot a mid-range load.
The cartridge was necked to fully hold the 38 spl 148 gn wadcutter bullet. It pushed the load at 38 spl target loads. It was found not practical to try and load the cartridge, as designed, to hot combat or hunting performances.
From my perspective, the cartridge design is fine for what it wa designed for but not too much else. There is a modification of that cartridge, and I don't know what it is called, but it moved the neck of the case up about halfway toward the case mouth and uses current 9mm or 38 spl slugs and get performance in the 38 Super and 357 Sig ranges.
Maybe some of the older shooters (ha! older than I am - lol) can give you a bit more info and possibly some others can give you more input on the updated design. HTH. Mikey.
