a 150 grain bullet shoots 3290 fps
No, the 300 ultra mag cartidge is not interchangeable with the 300 win mag.
300 Win Mag would be one.
300 win.
If your barrel is marked .300 Savage then you can shoot .300 Savage ammunition by any manufacturer. I do not know of a "300 Savage Winchester Magnum".
Which caliber?
Depends on how big the difference is and the range.
.300 WM is larger in calibre, it has a longer case, and it generates more energy.
Yes,Remington designed the round, and it can be fired in any good quality gun chambered for 22-250. Just as 300 Winchester Magnum was designed by Win, but any make of 300 Win Mag ammo can be fired in any good firearm designed for 300 Win Mag.
Rifle chambered in one of the cartridges named Winchester Magnum- such as the .300 Winchester Magnum- or .300 Win mag for short.
You will have to shoot to find out.
Only what it is chambered for.
Information about the 300 Win Mag, also known as the 300 Winchester Magnum can be found on the Wikipedia website. Videos about this item can also be found on YouTube.