Warning, a FWIW coming up!
Some folks wonder why, if early 20th century primers caused corrosion, why earlier cartridges and muzzle loaders didn't have the same problem. There are two reasons. One is that many of the old primers used mercury fulminate, which is not corrosive. The other is that the old guns used black powder.
But, while mercury fulminate does not cause rusting, it does destroy brass or copper cases, so when reloadable cases came out, the ammunition makers switched to potassium chlorate, which leaves the brass alone but ruins the gun if it is not immediately cleaned.
And the crud and build up resulting from firing black powder could be cleaned best by using hot water or a water based solvent. The same solvent, unbeknown to the shooter, also cleaned out the potassium chloride that rusted barrels.
So, the conjunction of reloadable cartridges and the advent of smokeless powder spelled doom for many barrels. Blame was placed on the new powder, on jacketed bullets, on high velocity, on the new barrel steel. On about anything but the primer. In the late 1920's a researcher for the U.S. Bureau of Mines discovered the real culprit, and the non-corrosive primer was developed, coming into common use in the mid-1930's. But early non-corrosive primers were not stable, so the U.S. chose to fight WWII with the old corrosive primer, except for carbine ammunition where corrosive primers would have ruined the gas system.
Jim