Re: Going to build a .338 and have some questions.
Don't get caught up in having to be at a certain velocity, as you stated wanting 2800+fps. Accuracy and tight velocity spreads would be the more important criteria. 100 fps make little difference at 1000yds with the 300gr SMK. Less than 3" difference in wind, and since I assume you will be dialing your drop, be more focused on your wind differences when comparing calibers. Pushing the 300gr SMK faster than 2700fps will do the job out to 1000yards and then some.. Having said that, when you jump up to the Chey-Tac based rounds there is a noticeable difference in performance.