RE: 22-250 vs 243 for coyote?
It is...... Kind of.
One thing you didn't take into account is the bullet dimeters.
The .243" bullets alone will be ballisticly superior to the .224" bullets but what you have to look at are the sectional densities if you are going to compare two bullets of the same design but of different calibers.
A 45 grain .224" bullet will have about the same sectional denisty as the 55 grain .243" bullet.
Since Nosler doesn't make a 45 grain ballistic tip the next closest bullet in .224" is the 40 grain.
AS the bore diameter increases the faster the same weight bullet can be driven, or a heavier bullet can be driven to the same velocities as a lighter weight bullet, given equal pressures inside the barrel.