The first thing I would ask is are there any special State laws that forbid the use of certain kinds of breech ignition systems where you live? Are there projectile restrictions? And since you have decided that magnum charges are not necessary, then what we need to determine is how much quality in the rifle do you want to PURCHASE.

Taking for granted there are no State Laws that forbid a closed breech for instance, and you're looking for an easy to clean rifle, then the Omega, and the Sidekick by H&R or NEF comes to mind. If you like a bolt type rifle, then I would suggest a Knight Disc Elite if you can find one. If the place you hunt or plan to hunt do not allow plastic projectiles, and you must use open sights, then I would suggest the White Ultra Mag in .504 if you can find one.

The thing a lot of people need to keep in the back of their minds when talking muzzleloaders is, they all have to be cleaned because of the powder we shoot. Some powders are more forgiving true, but you still have to clean them. If you are willing to donate ten additional minutes of your life to making sure the rifle is clean, almost any muzzleloader, even the Black Diamond you got rid of would be an excellent choice. If you want to clean something fast and easy and be done with it, then stick to the break open design or the stainless steel model rifles. They just seem to clean quicker. I personally would go after the White Ultra Mag also. My Ultra Mag so far has been a do everything asked of it rifle, and cleaning it seems almost too easy. I am always looking back over it to see why it comes clean so fast... These of course are just my opinions. Pick a rifle that pleases your eyes, wallet, and shooting abilities... Good luck in your search.