Generally a boat tail is less reliable in game than a flat base. A flat base should retain weight better. For small whitetail, you are probably fine.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball
Like with any other round used for hunting, shot placement is the first consideration. It is not wise to try to make up for a poorly-placed shot with a heavier bullet. A good shot with a 100-grain bullet out of a .243 will stop a deer in its tracks.