A .338-06 shooting 200 grain bullets @ 2900 fps?
That's what a .338 Win. Mag. gets with 200's at pressures about 53,000 CUP.
.35 Whelen's get about 2690 fps with 200-gr. bullets with peak pressurs about 52,000 CUP.
I think the pressure to do that is way, way over safe limits.
It is safe in my rifle and I'm not overpressure in anyway that I can tell. My load is 56.5 grains of RL 15 with a 200gr Hornady SP and I get 2880 (close enough to 2900 for me) across the chrony from my barrel, Hornady lists 57.1 grains as max load and lists 2900 fps as max velocity for the .338-06 with this 200 grain bullet. My rifle is a 1903 custom with 24" Lilja barrel nothing all that special about it and I get decent brass life out of Winchester .30-06 brass necked up haven't found any signifigant thinning of the case wall, primers look normal and pockets are tight in seven loads.
As with any load data you must work up to and figure out what is safe to shoot in your rifle. However I'm not working ouside the norms of a well published load. I can't run that fast with every 200 grain bullet but I can with the Hornady.