A firearm with replaceable grip comprising: a grip frame defining a grip mounting axis; a grip configured for mounting on the grip frame; and a rotary camlock mechanism configured and operable to lock and unlock the grip from the grip frame, the camlock mechanism rotationally movable between a first locked position preventing removal of the grip from the grip frame and a second unlocked position allowing removal of the grip from the grip frame; wherein the camlock mechanism comprises a rotatable locking cam rotatably mounted in the grip frame, the locking cam configured and positioned to engage the grip when the camlock mechanism is in the locked position and to disengage the grip when the camlock mechanism is in the unlocked position; and the locking cam is movably received in a rearwardly open circular receptacle formed in the grip frame; wherein circumferential sidewall surfaces of the locking cam include at least one recessed cam track configured to movably receive a mating grip retention locking protrusion formed in an inside surface of a cam receptacle, the/each cam track includes two opposing closed ends,, one end of the cam track being a locked end that defines a locked location or position of the locking protrusion in the track, the other end of the cam track being an unlocked end that defines an unlocked location or position of the locking protrusion in the track, the locking cam comprising an assembly slot for initially mounting the locking cam in the cam receptacle, and which is disposed substantially transverse to the cam track between the closed ends such that the locking protrusion can enter the assembly slot and then the cam track. a grip frame defining a grip mounting axis; a grip configured for mounting on the grip frame; and a rotary camlock mechanism configured and operable to lock and unlock the grip from the grip frame, the camlock mechanism rotationally movable between a first locked position preventing removal of the grip from the grip frame and a second unlocked position allowing removal of the grip from the grip frame; wherein the camlock mechanism comprises a rotatable locking cam rotatably mounted in the grip frame, the locking cam configured and positioned to engage the grip when the camlock mechanism is in the locked position and to disengage the grip when the camlock mechanism is in the unlocked position; and the locking cam is movably received in a rearwardly open circular receptacle formed in the grip frame; wherein circumferential sidewall surfaces of the locking cam include at least one recessed cam track configured to movably receive a mating grip retention locking protrusion formed in an inside surface of a cam receptacle, the/each cam track includes two opposing closed ends,, one end of the cam track being a locked end that defines a locked location or position of the locking protrusion in the track, the other end of the cam track being an unlocked end that defines an unlocked location or position of the locking protrusion in the track, the locking cam comprising an assembly slot for initially mounting the locking cam in the cam receptacle, and which is disposed substantially transverse to the cam track between the closed ends such that the locking protrusion can enter the assembly slot and then the cam track.