There's Pedersoli, Lyman, Austin Halleck and Traditions to name several.
While many people tout their hunting accuracy with heavy round ball loads out to 100 yards and more, that is probably the exception more than the rule. Here's the reason why: In order for a slow twist (round ball barrel) to shoot well with heavier PRB hunting loads, it
usually needs to have deep groove rifling , and a longer barrel also helps a lot by increasing velocity potential.
That's why so many people buy Green Mountain replacement barrels for their TC and Lyman guns, because GM barrels have deep groove rifling.
Now some guns can shoot shallow grooved rifling very accurately, but often these barrels require lighter (moderate) powder loads.
Of course, this is just an overall generalization to illustrate the concept, and not an absolute rule. (This same concept can also apply to 1 in 48" twist vs. 1 in 66" twist barrels. Slower twist barrels often require more powder for better accruacy.)
It's commonly understood and recognized that many of the factory produced shallow grooved rifle barrels have an effective hunting accuracy range of about 65-75 yards, more or less, depending on the amount of powder used, caliber, length of sighting plane (distance between front and rear sights) and characteristics of the individual rifle etc...
A shallow groove barrel may have a rifling depth of only .006 (maybe .008) while a deep grooved rifle barrel may have a groove depth of .010-.012. Plus some custom barrel makers have different
types and styles of barrel lands & grooves to select from. So, the number, as well as the actual shape of the lands and grooves (i.e.-rounded vs. squared) can vary and affect barrel accuracy and shooting characteristics.
In conclusion, if you buy a rifle that requires a relatively light or moderate powder charge to obtain longer range round ball hunting accuracy, than it may be beneficial to use a larger caliber ball to help insure that you'll get the penetration you need to get the job done. It really depends on your hunting range and what your accuracy needs require.