So, the Amercan hunter would not be best suited with short light rifle in a caliber that will take deer/antelope/elk at 0-300 yards?
There are tons of rifles that already do that just fine, and with less recoil. I can find no niche for the round. For animals smaller than elk a 7-08 is a better choice. For animals elk size or larger it won't beat a 308.
The 338 Fed shoots the same bullet weights 50-100 fps faster than a 308 and 50-100 fps slower than 30-06.
Compared to a 308 it has a very slight edge in energy at close range, but the more aerodynamic 308 bullets passes it in both trajectory and energy before the 200 yard mark.
A .308 bullet of approximately the same weight will not only be more aerodynamic and retain energy better at long range, it will also outpenetrate a comparable weight .338 bullet at any range. You'd have to move up to a 225 gr .338 bullet to match the penetration of a 200 gr. 308 bullet. The .003" difference in diameter is a non-issue. After bullet impact and expansion there wouldn't be any measurable difference.
My 308 weighs under 6 lbs scoped so I've got a short light rifle already that will do the same thing. Instead of dreaming up the 338 Fed, they should have offered a factroy loaded 200 gr Nosler Accubond @ around 2550 fps.