PRC? Because it fits in a short action, works inside of the magazine with long VLD style bullets, it's what most of the shooting public wants, and the shooting industry needs to stay innovative to compete. We had a very similar discussion in
USAF Ret thread "What am I Missing".
There are a lot of cartridges out there that can be used in the same capacity as the 6.5 PRC. The PRC is a long range cartridge that starts to shine beyond 500 yards. For a 100-300 yard range guy, average Eastern white tail hunter, and the majority of Western big game 500+ yards rarely enters the equation. Then there are shooters who want to buy off the shelf ammunition and when was the last time you saw SAAMI standard 6.5-06 A-Square ammunition on the shelf?