In a recent paper, Jain and Sodha 1) have discussed the internal ballistics of a supergun (Hochdruckpumpe) designed by Coenders 2) during the second world war. In the present paper it is shown that their theory is the same as that for the burning of moderated charges in an orthodox gun (Kapur 3) 4)) and that their implicit assumption of the powder in the rth chamber being ignited only when the powder in the first (r−1) chambers has been completely burnt out is not likely to lead to an efficient supergun. An alternative theory without this restriction and including their theory as a particular case is discussed and its relation with the general theories of composite and moderated charges (Kapur 3) 4) 5) 6) 7)) is given.