Depends what you're definition of accuracy is, and how much you're willing to practice. Initially, can you hit a paper plate at 25 yards 75% of the time, sure. Can you hit a paper plate at 50... maybe a few times. With practice, maybe better.
You might be able to fit a set of round barrel, muzzle loader sights to the rifle with epoxy, or have some inexpensive sights adapted or fit by a gunsmith. Look at muzzle loader, shotgun and rifle sights in the Brownell's website... see if you come across something with potential, or visit a gunsmith and see if they'll take pity on you.
