Once you get it tuned proper, figure out the in's-out's and tricks to the flint lock, you should get one hole groups at 50yrds and 4-5" groups possible 3" at 100. It's the open sights and eyes that defeat most people.
In other words it'll shoot better than most people.
But theres work to do experimenting with different loads, patch, lube, etc,,,
Have fun with it first, most folks have a blast just getting the thing to go bang and makin smoke,,