Re: Building from what I have
I have taken remington 700s, brownings A bolts, and savage weather warriors out of the box and have stacked 5 rounds into a sub 5/8 group with all of them by doing the following:
Adjust factory trigger as low as it will go without getting slam fires. If you have the money, get a jewel trigger and never look back. My brothers sendaro almost cost him a trophy bull due to a slam fire problem in the heat of the moment.
Break the barrel in using a tried and tested method. If you don't think this works, chrono the first 20 rounds out of the rifle. They will have very high extreme spreads. Once the barrel is broke in and the copper is removed, sit back and watch the ES shrink and your groups tighten.
reload,reload,reload. Playing with different powders, and seating depths till you get groups near the 1/2 inch mark. This might be your biggest contribution towards accuracy
Double check to make sure all the action screws are properly torqued. Lap the scope rings if possible. Make sure the scope has perfect alignment.
The rem sendaro or savage long range hunter would be excellent out of the box rigs. I'd get the 7mm if it were me. I could explain why, but it would take more time than I have right now! PM me if you want more info.