Easy, to sell rifles. There are a lot of folks who just have to have whatever "Latest Thing" comes down the line so firearms manufactureres are only too happy to concoct a "Latest Thing" for them every couple of years. Each "Latest Thing" is always accompanied by a ton of marketing hype officially proclaiming it as the greatest advancement since they first put rifling in a gun barrel. And of course most of that marketing hype is basically just pure bull###t The 300wsm offers no ballistic advantage over the 300 wm.As for thetheoretical claims of being more accurate? Even if true, you are talking a very minute fraction here. A difference so small that it is easily brushed aside toabsolute insignificance by the variances in the particular rifle set up. Reduced Recoil? I'm sure fired from the same weight gun there wouldpossibly be a measurable difference but of course the 300 wsm rifle is going to weight less than the standard sized 300 wm rifle. A practical difference that has a far greater impact on felt recoil than the hull shape of a cartridge.