I have a T/C Encore 209X50 and shoot it using the recommended data from T/C to roughly .454 Casull ballistics without a problem.

I took this 6X6 bull elk at approx. 75 yards with one shot, and this photo was featured in one of T/C's earlier catalogs.

I have video footage of a doe antelope I shot with the same load and it literally knocked her off her feet.

A T/C .50 caliber muzzleloading pistol loaded correctly gives up nothing to a .454, ballistics-wise, in my opinion.