I'm not so sure that it was merely a case of magnumitis. After all the superb 358 Norma Magnum failed to reach any popularity here in the states. The Norma chambering had a couple of things going against it, one was Winchester's 338. The 338 and 358 were closely matched, but there were really not many suitable bullets for the 358 and several good ones for the Winchester. It didn't help the Norma that it was not American manufacture either. I suppose the 358 Winchester failed for some of the same reasons, it didn't really do anymore or any less than something that already existed. I don't think the shooting public at that time had the expendable income that most shooters have today and to alot of people one gun that handled the game they hunted was enough. It's true that the flatter shooting cartridges were the biggest sellers at that time, as they are today. By and large the 30/06, 270, 7mm's, 300's, 308 and such are the life blood of the industry. The exceptions seem to be the 30-30 and 45/70. Don't forget, the time the 358 came out the public was largely enthralled with flashy, Hollywood type things. The 358 was a workhorse of a cartridge, but not as dramatic as a Weatherby or some other magnum. It just did what it did very very well. However, it really didn't do anything that could not be done with an '06, 270, 7 Mag, 300 Mag, or 30-30. It wasn't rooted tradition the way the 30-30 was, nor did it have the military blessing of the '06 or 308, and was chambered in short range brush busting rifles at a time when the industry was trying to dispell the "brush busting myth". The 358 Win saw a rise in popularity several years back when quite a few custom gun makers began chambering bolt actions for them, but without good strong factory loads and the introduction of the 35 Whelen, interest just kinda died. Too bad, it is a good cartridge for suited conditions. Will it do something that much better than another more popular round? I don't think so, but it is good.