Abstract: A caulking gun has a built-in cutter being formed between a handle (14) and a trigger (18) for cutting off a tip (34) of a caulking spout (36). The cutter has a cutting blade (62) being mounted in the handle and a cutting forwarder (40) for pushing the spout to the blade for cutting. One end of the cutting forwarder together with a tension spring (46) is pivoted in the trigger and another end reclines against the handle. A blade slot (60) on the top of the forwarder covers the blade for finger protection. A pair of openings (54, 55) are located in the two side wells of the blade slot of the forwarder for receiving the spout from either right side or left side of the caulking gun for cutting. The surfaces of the openings force a spout inside the openings to the blade with an angle less than 90.degree. for smoothly spout cutting while the trigger is squeezed.

Abstract: A caulking gun having a fixed first bearing surface, and an engagement member for preventing rearward movement of a plunger shaft while permitting forward movement thereof. Following termination of forward movement of the plunger shaft in response to operation of a handle mechanism of the gun, the plunger shaft selectively can be moved rearwardly a predetermined distance in response to cartridge back pressure. In an alternative mode of operation, the rearward movement is substantially prevented for effecting precise control and smoothly continuous feeding of media from the gun. In one configuration, a shifting link permits movement of the plunger shaft together with the engagement member up to a distance E when a control surface is positioned for providing forward movement of the engagement member in response to forward movement of the plunger shaft.