Whats the advantage of a boat tail design over the flat base.
Typically a Boat Tail Bullet will have a higher Ballistic Coefficient than a Flat Base Bullet of the same weight and same basic design. This allows a Boat Tail bullet to travel through the air with less resistance.
As Greybeard stated the 65gr. Hornady V-MAX and 70gr. Nosler Ballistic Tip are both excellent Varmint / Predator Bullets in .243 Caliber. While I do not have any experience with the 65gr. Hornady V-MAX I have read many good things about the bullet. I do have a fair amount of experience with the 70gr. Nosler Ballistic Tips having used them in 6mm-223 Handguns as well as .243 Rifles and Handguns.
One thing is for sure the 70gr. Nosler Ballistic Tip from a .243 (Rifle or Handgun) will anchor a Coyote for keeps. However they are not very fur friendly if you are concerned with saving pelts. I have always obtained very good accuracy with the 70gr. Nosler Ballistic Tips as well, regardless of what velocity I was pushing them at.
In the end the Boat Tail vs Flat Base Bullet debate can get trickier. Some Rifles just do not shoot Boat Tail Bullets as accurately as Flat Base Bullets, but then the reverse is true also. In the end your rifle will let you know by the size of the groups it produces as to which it prefers.
Larry