Re: 7mm-300 winmag
The 300 winnie and the 7mm Rem mag cases are VERY close in design. It is alot of headache and expense to go with a wild cat that offers such little performance gains IF any over a readily available cartridge. If you want a 7mm wild cat, dont joke around. Use a bigger case.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.