Barrel length and powder burn rates affect pressure, so your barrel length will matter, otherwise, in 26" or shorter barrels, 2800 with a 300 grain bullet is already into pressure.... and very questionable you will get 2850 without blowing primers or something more important.
If 2800-3000 with heavy bullets is your goal in 338L, the Remington 700 is not recommended by any of the gunsmiths I know that have built 338L on a 700.
If it's a hunting rifle with a 225 grain bullet, and the right combination slow burn powder, 3000 is safe. If a target rifle, 2900 with a 250 and the right powder, you can find a safe combination, but, you can also find a fast peak high pressure load that isnt safe very quickly. One mistake can cost you an eye, it's not worth it.
I will reiterate, if 2800-3000 is your goal, there are much better and stronger choices to build a 338L on than the 700.
As I said in my first post, I have one in a 700. My second one was built on a much stronger action because, 10 years ago, the big name gunsmiths were afraid of 700's with high pressure loads.
Remington quit building them on the 700 for liability reasons. That should be sufficient information to point you to a stronger action and help you decide a different course.
Best to you, vr.