I agree with shooting before buying bulk. I got 2 30-06s with same length and twist. One shoots Hornady interlocks the other partions 1MOA, and they shoot the other brand awful.
I don't hunt deer with with my 243. But I did read an interesting article in a Lyman manual from late 90s. They got some formula to base weight of animal and range and rate calibers. Granted I a skeptical a bit, but I get speed and energy. They rated the 243 higher than 30-30. Now many people the big metplate of lever actions have knock down power. 243 obviously will have longer range though.