I am doing my 1st build and was wondering what barrel to go with? There are so many options. I plan on using a Savage action. One I have been looking at are...Douglas Fluted...Shilen...Pacnor...ect...ect.. It will be calibered in either a 7mmMag, 7WSM, 7mm-300WSM or 7SAUM? Haven't figured out which yet. Thoughts on that to??