Re: High Powered 30 cal???
Seems like you would be suited well with the 300 RUM. You may not get quite 3000 FPS out of the 240 SMK (will depend on bbl length) but you will get it close for sure. This case can easily be built on a remmy or winny action. The 30-378 is a bit more potent but seems more finiky overall than the 300 RUM and most smiths wont build on on a rem or win action. Some think it is out right dangerous.
Just my .02
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.