A reload assembly comprising: a shell housing including an inner housing portion defining a longitudinal axis and an outer housing portion, the inner housing portion having an outer surface defining an annular recess; the annular recess radially reducing the inner housing portion along the longitudinal axis the annular recess having a distal end defined by a stop surface; an annular cavity defined between the inner housing portion and the outer housing portion; a staple cartridge supported on a distal portion of the shell housing, the staple cartridge having a plurality of staple pockets, each of the staple pockets receiving a staple; a pusher supported within the annular cavity, the pusher axially movable between a retracted position and an advanced position to eject the staples from the staple cartridge; a one-way collar received about the inner housing portion within the annular recess, wherein the one-way collar is axially movable from a retracted position distally to an advanced position, wherein the stop surface is configured to prevent further distal movement of the one-way collar; a knife carrier supporting a knife, the knife carrier including a body defining a central bore receiving the inner housing portion such that the knife carrier is axially movable about the inner housing portion between advanced and retracted positions; a resilient snap-ring axially fixed within the central bore of the knife carrier and releasably engaging the one-way collar such that the one-way collar is movable from its retracted position to its advanced position in response to movement of the knife carrier from its retracted position to its advanced position; wherein the snap-ring is movable to a position proximally of the one-way collar when the one-way collar is in its advanced position; wherein when the one-way collar is in its advanced position and when the resilient snap-ring is released from the one-way collar and positioned proximal to the one-way collar, the one-way collar obstructs distal movement of the snap-ring and thus the knife carrier to its advanced position. a shell housing including an inner housing portion defining a longitudinal axis and an outer housing portion, the inner housing portion having an outer surface defining an annular recess; the annular recess radially reducing the inner housing portion along the longitudinal axis the annular recess having a distal end defined by a stop surface; an annular cavity defined between the inner housing portion and the outer housing portion; a staple cartridge supported on a distal portion of the shell housing, the staple cartridge having a plurality of staple pockets, each of the staple pockets receiving a staple; a pusher supported within the annular cavity, the pusher axially movable between a retracted position and an advanced position to eject the staples from the staple cartridge; a one-way collar received about the inner housing portion within the annular recess, wherein the one-way collar is axially movable from a retracted position distally to an advanced position, wherein the stop surface is configured to prevent further distal movement of the one-way collar; a knife carrier supporting a knife, the knife carrier including a body defining a central bore receiving the inner housing portion such that the knife carrier is axially movable about the inner housing portion between advanced and retracted positions; a resilient snap-ring axially fixed within the central bore of the knife carrier and releasably engaging the one-way collar such that the one-way collar is movable from its retracted position to its advanced position in response to movement of the knife carrier from its retracted position to its advanced position; wherein the snap-ring is movable to a position proximally of the one-way collar when the one-way collar is in its advanced position; wherein when the one-way collar is in its advanced position and when the resilient snap-ring is released from the one-way collar and positioned proximal to the one-way collar, the one-way collar obstructs distal movement of the snap-ring and thus the knife carrier to its advanced position.