American Knight - 22" barrel Blued Composite stock, no recoil pad. Depending on when it was made the stock is either hollow or solid. Most were hollow, I believe it was only the last year of production that they made solid stocks for these. The sights are cheaper than the other Knight rifles and I believe only the front sight has a fiber optic. They also carry a cheaper trigger that the other Knight rifles. On the plus side the Knight plunger action is still in use and they still make parts for it. The plunger action is also cleaned as one piece and this is a plus.
T/C Black Diamond - Could be 22" barrel or 26" barrel. I don't know if they ever made a 24" barrel for them.The warranty is also transferable. Hollow stock but with a cheap recoil pad. The recoil pad can be replaced with a sims pad (recomended if you get one). These had very good sights standard. You mention a 4X scope. Unless it cost more than 150 new I'd trash it. Most cheap scopes are just that. There are a few negatives with the black diamond. The QLA is unneccisary and folks have reported problems with some of these being off center. Also the plunger action is composed of many pieces to clean.
I guess if it were me I'd go with the American Knight. I love the single piece plunger and the reduction in cleaning is worth it. I'd put a scope on it so the sights are not a negative to me. The stock is a problem, but neither the BD nor the AK have good stocks so that is not a deciding factor. I would probably investigate the possibility of purchasing a wolverine or bighorn stock for it. A slip on sims pad is a good option as well. The trigger is probably ok since Knight triggers are almost universally excelent. You could probably replace it later on if you didn't like it. The American Knight is basically a stripped down Wolverine or bighorn.
