A surgical stapler (210; 410) comprising: (a) a first stapler half (214; 414) comprising: (i) an anvil surface (266; 466) having a plurality of staple forming pockets, and (ii) a proximal pivot projection (270; 470) extending laterally relative to a longitudinal axis of the surgical stapler, wherein the proximal pivot projection has a non-circular transverse cross-section; and (b) a second stapler half (212; 412) configured to releasably couple with the first stapler half and to pivot relative thereto about the proximal pivot projection, wherein the second stapler half comprises: (i) an elongate member (216; 416) having a distal portion operable to deploy staples toward the anvil surface and at least one proximal notch (226; 426) configured to pivotably receive the proximal pivot projection of the first stapler half, and (ii) a locking member (280; 480) configured to translate along the longitudinal axis of the surgical stapler between a distal locked state in which the locking member selectively captures the proximal pivot projection and a proximal unlocked state in which the locking member selectively releases the proximal pivot projection for coupling and separating the first and second stapler halves, respectively, wherein a portion of the proximal pivot projection is configured to selectively frictionally engage at least one of a proximal surface of the at least one proximal notch or a distal surface of the locking member in response to rotation of the first stapler half away from the second stapler half about the proximal pivot projection to an open state in which the first and second stapler halves assume a predetermined maximum angular orientation relative to one another and remain releasably coupled together at their proximal ends. (a) a first stapler half (214; 414) comprising: (i) an anvil surface (266; 466) having a plurality of staple forming pockets, and (ii) a proximal pivot projection (270; 470) extending laterally relative to a longitudinal axis of the surgical stapler, wherein the proximal pivot projection has a non-circular transverse cross-section; and (i) an anvil surface (266; 466) having a plurality of staple forming pockets, and (ii) a proximal pivot projection (270; 470) extending laterally relative to a longitudinal axis of the surgical stapler, wherein the proximal pivot projection has a non-circular transverse cross-section; and (b) a second stapler half (212; 412) configured to releasably couple with the first stapler half and to pivot relative thereto about the proximal pivot projection, wherein the second stapler half comprises: (i) an elongate member (216; 416) having a distal portion operable to deploy staples toward the anvil surface and at least one proximal notch (226; 426) configured to pivotably receive the proximal pivot projection of the first stapler half, and (ii) a locking member (280; 480) configured to translate along the longitudinal axis of the surgical stapler between a distal locked state in which the locking member selectively captures the proximal pivot projection and a proximal unlocked state in which the locking member selectively releases the proximal pivot projection for coupling and separating the first and second stapler halves, respectively, (i) an elongate member (216; 416) having a distal portion operable to deploy staples toward the anvil surface and at least one proximal notch (226; 426) configured to pivotably receive the proximal pivot projection of the first stapler half, and (ii) a locking member (280; 480) configured to translate along the longitudinal axis of the surgical stapler between a distal locked state in which the locking member selectively captures the proximal pivot projection and a proximal unlocked state in which the locking member selectively releases the proximal pivot projection for coupling and separating the first and second stapler halves, respectively, <EOS>