Fred Rodney was the owner,operator and chief cook and bottle washer of Gonic Arms. He made an in-line muzzleloader with tight tolerances that could use large powder charges.
He also made a muzzleloading TC Contender barrel in 38,44,45 and 50 calibers. He had a 16 1/4" and a 23 " barrel. I once owned a 16" 45 with a muzzle brake. I sold it because it was a pain to load due to the brake and hoped to buy a 50 in the near future.
Sad to say, Fred passed away and so the company no longer exists as it once did. I had heard that his son does some work and can do a custom barrel but this is second hand information. They show up at the gun show circuit now and then.