Not planning on jumping into anything specialized right now, I just like doing research and having a scientific reason for things. So you say the sharper angle and longer neck help accuracy and barrel life, in what way do these things help? Do you have evidence to back this up? Not criticizing you just trying to seperate fact from fiction/opinion.
Benchrest shooters have done all the work for us, just look at what was the most accurate cartridges:
* before the 80s, 222 Rem basically a scaled down 30-06
* after the 80s, 6mm PPC basically of super-optimized 220 Russian necked-up to 6mm
You should simply read about why 6mm PPC is so good and why similarly designed cartridges like 6.5 Lapua, 300 WSM, 6mm Creedmoor and 6.5 Creedmoor are simply better shooting cartridges.
(One important point, a 308 Win is a 30-06 optimized for modern propellant powder and functioning in automatic mechanism - it feed well, hit hard at medium range and is very efficient)
As for the difference between 6x47 Lapua and 6mm Creedmore, there are almost none from a design and performance point of vue.
Final comment, the 6.5x47 Lapua is almost unbeatable at 300m shooting and is almost as accurate as the 6mm PPC and 6mm BR.
There are many considerations but these 6mm cartridges (6mm PPC, 6mm BR, 6mm XC, 6x47 Lapua and 6mm Creedmore) are the low-recoil winners.
6mm XC, 6x47 Lapua and 6mm Creedmore feed well from a box magazine and they are all excellent.
243 Win is a great cartridge but suffers from the same problems as 270 Win: to much case capacity for given bullet weight because of too low standard rifle twist.
(270 Win is 1-10", 243 Win is 1-9 while 280 Rem is 1-9" , 6mm Creedmore is 1-8" allowing to use higher sectional density, high BC bullets better at long range).
Alex