Some say that you'll get a clearer image if you're not at the scopes max magnification. With that line of thought, the 6-24 @ the Hunter legal 16x would be the better choice.
Make sure whatever you buy focuses down to 10yards. Which is another reason why the 6-24x is probably a better choice. Most scopes will focus to a shorter distance if they're not set at maximum magnification. So the 4-16 might only do us down to 11 or 12 yards @ 16x while the 6-24x might be more likely to focus down to a true 10yards (or less) when set to 16x.
And also be aware that some manufacturers advertise that their scopes focus down to 10meters (11 yards). Being able to determine 10 from 11 yards is usually the most critical distance differential that you'll need to be able to determine. Pellet trajectory is climbing from the bore line to the line of sight (scope) the most from 10 to 11 yards than any other 1 yard increment. In summary, you want minimum focus distance of 10 yards, not 10 meters.