I wasn't able to get your link to come up so I don't know if you have a scope with your rifle or not. If not buy the best scope, rings, and bases you can afford. Make sure scope is mounted properly with bases and rings secured with Loctite. Bore sight it to get you on paper then take it out and shoot it for final zero. What are you planning to do with it, hunting or target shooting or both? The Remington 700 is a very accurate platform to build on but improvements can still be made to make it more so. Do you handload your ammo? Handloading is the best way to get the maximum accuracy out of any rifle regardless of make or model. If you use factory ammo Federal Gold Medal Match is probably the most accurate target ammo in my opinion. Barrel break in is another subject matter that some believe in and others do not. The internet has tons of articles for both sides of that issue. I personally don't get that worried about it to any great degree. I clean the bore very well prior to the first shot, shoot two or three and clean it for the first 20 to 30 rounds and then it's business as usual. My three 700's are all well under MOA, with handloads, following that process. 300 yards can be easily accomplished, in theory, with most hunting weight bullets, beyond that it gets a little more technical as more and more variables come into play. Other than that it's about pulling the trigger and learning the rifle. Good luck with it.