There is an old saying - "You cannot miss a bear enough times to kill it" Better to hit with something you can shoot well and easily then to fumble with a more powerful weapon.
I agree with that to a certain extent, but there are times when the extra horsepower really can't be replaced.
When you are taking a charge from any type of large predator, lion, tiger, bear, etc you want enough gun. That .375 H&H that you and your buddies laughed about seems like a good option with 800 pounds of pi$$ed off bear closing the distance between the two of you. In fact, it seems a lot better than the .243 that you brought instead because you enjoyed shooting it.
Practice makes a competent shot with a rifle. You will get used to recoil when you practice with it.
Obviously most pond issues can be solved with any centerfire rifle .22 caliber and above. So, being undergunned really isn't a concern here.
