If you're hunting deer, a roundball at anything under 75 yards is fine. A 270 grain ballet is even better. You've increased the weight of the projectile and it will have more energy at the end of flight. I would not hesitate shooting a deer with a roundball or ballet out of a .50 caliber if it were a good placement shot. I would not take sketchy shots, if you know what I mean.

I live in bear country. Were I to hunt bear with a roundball, it would have to be tucked behind that shoulder blade. You know how thick that is and how much it can soak up. But if you tucked that roundball or ballet behind it, and into the vitals, it should work. Although shot placement is critical. The ballet would be a better choice here for bear.

If the 460 grain No Excuse Conical bullets shoot well for you out of that twist, and you can get at least 70 grains of powder under it, and accurate, a deer or even a bear would not stand a chance IMO.

If I remember right ( and correct me if I am wrong) you have a Cabela's Hawkins. I shoot a Lyman made by Investarms. Your Cabela's is made by Investarms. My 1-48 twist Trade Rifle will shoot a powerbelt very well. That would be another option. Especially on bear. You might look at some of the heavy and more solid constructed powerbelts and see if they shoot well for you. My rifle shoots them with 80 grains of powder. I have a .54 caliber and normally shoot a 405 grain Powerbelt. I would shoot either of them animals, any day of the week with that powerbelt.