Is it all right for Old Joe to sell the gun to Dave?
The answer is more than likely no. Young Dave Saunders is seventeen years old; his whole family lives and works on Jim Hawkin's plantation. When Dave asks to borrow Old Joe's gun catalog, Joe is intrigued. He offers to sell Dave his gun for two dollars if Dave is interested in purchasing one.
Dave can't believe his luck: all he has to do is to ask his mother for some money out of his pay in order to buy the gun. However, when Dave asks his mother for the money to buy the gun, she balks. She tells him that he is just a boy and proceeds to lecture him about his foolish notions. She also asserts that the only reason she has Jim Hawkins hand over Dave's pay to her is because Dave doesn't appear to know how to spend his money wisely.
However, Dave soon wears her down by promising that he will bring the gun back to her as soon as he purchases it. He also promises that the gun will belong to his father. However, Dave's fascination with the gun soon gets the better of him. He tells his mother that he has left the gun outside after the purchase. The next day, he straps the gun to his thigh and slips out of the house without going in to breakfast.
While taking out the mule to do some plowing for Joe Hawkins, he gives in to the temptation to fire the gun. However, Dave's inexperience is apparent when he fails to take into account the need to prepare himself for the backward momentum (or recoil) of the gun when it is fired. As a result, his aim skews in the direction of the mule. The mule is shot and eventually dies from her wound. Although Dave is desperate to prove to himself and to everyone else that he is mature enough to handle a gun, his lack of experience causes the death of the plantation owner's mule and also puts him in debt to the tune of fifty dollars (for the mule). In summary, Old Joe should not have sold the gun to Dave due to Dave's youth and inexperience.