I think that any decently-made ML should be able to shoot 2" 3-shot groups or better at 100 yards with some experimenting. All the experimenting with different loads, bullets is at least half the fun of ML shooting for me. I've seen that 1" groups or smaller at 100 yards are possible with an ML, but I'd find it hard to believe if someone claimed to get that kind of accuracy every single time they go out shooting, regardless of weather conditions, wind, etc.

But for hunting purposes, I'm happy with a ML that will consistently shoot 2.5" groups or better at 100 yards. Of course I always try and tweak it to get the best I can, but a 2.5" group will put meat in the freezer every time at muzzleloading ranges.