An airgun for use with a projectile supply having a housing and a passageway extending along a supply axis into which the projectile supply positions a projectile when the passageway is open, the airgun comprising: a compression tube having a transfer port from which the compressed air passes during firing of a compression piston; a bolt with a leader portion sized to pass into the projectile supply passageway; a bolt positioner that moves with the bolt; a breech having a projectile supply holder adapted to hold the projectile supply with the projectile supply passageway substantially in line with a bore of a barrel characterised in that the breech is further providing a bolt guide positioning the bolt between the compression tube and the projectile supply holder for movement along a path that is generally co-axial with the passageway and the bore; a bolt positioner guide positioned to interact with the bolt positioner to advance the bolt between a first position extending through the passageway and a second position retracted from the passageway; a pivot joining the breech to the compression tube for movement between a firing position where the transfer port, the passageway and the bore are substantially aligned and a reloading position; a cam surface that moves with the compression tube when the compression tube is rotated relative to the breech; a gas flow path between the transfer port and a firing location in the bore; wherein the cam surface and the bolt positioner are configured so that rotation from the firing position to the reloading position causes the cam surface to drive the bolt positioner against a bias from the first position to the second position to open the passageway; and wherein the cam surface and the bolt positioner are configured so that rotation from the firing position to the reloading position causes the cam surface to drive the bolt positioner through the passageway to drive a projectile in the passageway to a position where pressurized gas in the firing location will thrust the projectile through the bore. a compression tube having a transfer port from which the compressed air passes during firing of a compression piston; a bolt with a leader portion sized to pass into the projectile supply passageway; a bolt positioner that moves with the bolt; a breech having a projectile supply holder adapted to hold the projectile supply with the projectile supply passageway substantially in line with a bore of a barrel characterised in that the breech is further providing a bolt guide positioning the bolt between the compression tube and the projectile supply holder for movement along a path that is generally co-axial with the passageway and the bore; a bolt positioner guide positioned to interact with the bolt positioner to advance the bolt between a first position extending through the passageway and a second position retracted from the passageway; a pivot joining the breech to the compression tube for movement between a firing position where the transfer port, the passageway and the bore are substantially aligned and a reloading position; a cam surface that moves with the compression tube when the compression tube is rotated relative to the breech; a gas flow path between the transfer port and a firing location in the bore; wherein the cam surface and the bolt positioner are configured so that rotation from the firing position to the reloading position causes the cam surface to drive the bolt positioner against a bias from the first position to the second position to open the passageway; and wherein the cam surface and the bolt positioner are configured so that rotation from the firing position to the reloading position causes the cam surface to drive the bolt positioner through the passageway to drive a projectile in the passageway to a position where pressurized gas in the firing location will thrust the projectile through the bore.