A carriage (240, 240', 340) for use with a surgical guide, comprising: a housing (250, 250', 350) having a proximal end (250p, 250p', 350p), a distal end (250d, 250d', 350d) opposed to the proximal end, opposed first and second side surfaces (250r, 250s, 250r', 250s', 350r, 350s) that extend between the proximal and distal ends, and opposed first and second facial surfaces (250f, 250g, 250f, 250g', 350f, 350g) that extend between the proximal and distal ends and the first and second side surfaces, the housing (250, 250', 350) further having a guide-receiving opening (244, 344) formed therein. the guide-receiving opening (244, 344) being configured to receive an arm of a surgical guide along which the carriage (240, 240', 340) is configured to translate; and a bullet receiver (246, 246', 346) rotatably coupled to the housing 250, 250', 350), the bullet receiver (246, 246', 346) having a bullet-receiving opening (242, 242', 342) formed therein to receive a bullet (270, 470) for use with a surgical guide associated therewith, the bullet receiver (246, 246', 346) being rotatable between a receiving position in which the bullet-receiving opening (242, 242', 342) is open towards an environment outside of the housing (250, 250', 350) to receive a bullet (270, 470) for use with a surgical guide associated with the carriage (240, 240', 340), and a locking position in which the bullet-receiving opening (242, 242', 342) is rotated towards the housing (250, 250', 350) to place a bullet (270, 470) disposed therein in a locked position in which said received bullet (270, 470) cannot translate between the two side surfaces (250r, 250s; 250r', 250s'; 350r, 350s) of the housing (250, 250', 350) or between the two facial surfaces (250f, 250g; 250f', 250g'; 350f, 350g) of the housing (250, 250', 350). a housing (250, 250', 350) having a proximal end (250p, 250p', 350p), a distal end (250d, 250d', 350d) opposed to the proximal end, opposed first and second side surfaces (250r, 250s, 250r', 250s', 350r, 350s) that extend between the proximal and distal ends, and opposed first and second facial surfaces (250f, 250g, 250f, 250g', 350f, 350g) that extend between the proximal and distal ends and the first and second side surfaces, the housing (250, 250', 350) further having a guide-receiving opening (244, 344) formed therein. the guide-receiving opening (244, 344) being configured to receive an arm of a surgical guide along which the carriage (240, 240', 340) is configured to translate; and a bullet receiver (246, 246', 346) rotatably coupled to the housing 250, 250', 350), the bullet receiver (246, 246', 346) having a bullet-receiving opening (242, 242', 342) formed therein to receive a bullet (270, 470) for use with a surgical guide associated therewith, the bullet receiver (246, 246', 346) being rotatable between a receiving position in which the bullet-receiving opening (242, 242', 342) is open towards an environment outside of the housing (250, 250', 350) to receive a bullet (270, 470) for use with a surgical guide associated with the carriage (240, 240', 340), and a locking position in which the bullet-receiving opening (242, 242', 342) is rotated towards the housing (250, 250', 350) to place a bullet (270, 470) disposed therein in a locked position in which said received bullet (270, 470) cannot translate between the two side surfaces (250r, 250s; 250r', 250s'; 350r, 350s) of the housing (250, 250', 350) or between the two facial surfaces (250f, 250g; 250f', 250g'; 350f, 350g) of the housing (250, 250', 350).