Gomer
AH enthusiast
You may be right with the 300 PRC, I absolutely can see it coming up short just as the 300 RUM and 30 Nosler did. Where you are wrong will likely be the 6.5 and 7mm PRC. The 6.5 PRC has found a solid niche with the sheep hunters, it is the modern rendition of a 270 with just a better bullet. The 7 PRC will absolutely be the down fall of the 7mm rem mag and this is coming from a die hard rem mag fan. Sure a custom rem mag with custom hand loads can do what a 7 PRC does but with 10 times more cost and effort. I will go so far as to wager that the 7 PRC starts to take a share away from the 300 WM even.
You are correct, these rifles really do not do anything more than their older counterparts. They do the same things but more efficiently. The days of 26" barrels are coming to an end and the older magnums drop performance rapidly when put in suppressor friendly 18-22" barrels. They also are not capable of shooting the longer more modern bullets without significant work.
Don’t count out cartridges with a 60+ year head start. Besides, most of the older cartridges that share bore sizes with the PRCs are getting twist updates. Its more cost effective for all chamberings of a particular bore size to share a twist rate. That’s why you can get Sako and Tikka 7mm Rem Mags with 1 in 9.5 twists cheap right now. The new ones at full price have faster twists.