 On the outside of the gun is a shell replenishment gear with an extending arm which can be adjusted to collect a projectile at ground level or from the back of a truck.From this point onwards, the projectile is untouched by human hand; once it reaches the magazine in the turret, it is moved by the magazine hoist to its selected storage row and is then moved along the row by the action of the rigidly mounted pawls.Hence the title "rigid pawl magazine".