thereby opening the axial bore 26 to communication in the space from the auxiliary lines 34 36 into the main bore 28 of the production tree 27 as the engagement of the locking plug 80 with the axial bore 26 forms a pressure seal isolating the axial bore 26 from ambient a flushing fluid may be introduced through one or both of the auxiliary lines 34 36 and into the axial bore 26 below the profiles 84 the flow of the fluid coupled with pressure in the fluid can be used for urging the ball 62 1 downward past the lower end of the axial bore 26 through swab valve 65 and into the wellbore 30 a plan view of the magazine assembly 54 is provided in fig7 in this example it can be seen that the cylinder 58 is provided with a plurality of chambers 60 1 n shown formed in a generally circular path along the outer periphery of the cylinder 58 in the example of fig7 each of the chambers 60 1 n is provided with a corresponding ball 62 1 n embodiments exist wherein one more chambers 60 1 n may be empty or include more than one ball further provided in the example embodiment of fig7 are notches 92 provided on the outer periphery of the cylinder 58 in the example embodiment of fig7 the notches 92 have a generally triangular shaped outline and extend the entire height or thickness of the cylinder 58 alternate.