I had one on my Prohunter for a while. I sold it and bought another from Thompson. Accuracy and consistency was much better. One of my buddies has an accuracy barrel from E. Arthur Brown Co., and it is a great shooter (.223).
Maybe I've been lucky but I have a CVA optima elite with the .50 cal muzzleloader and a .223 barrel and they are both excellent. The .223 is a tack driver that if I do my job it's less than an inch @ 100yds. The muzzleloader is about 1.5 inches to 2 inches @ 100yds but I haven't shot it too much yet. I would highly recommend them. If you've had problem barrels I'd get in touch with the company.