Unlike the designs of other early semi-automatic pistols, Browning's design used a full-length slide that covered the full length of the barrel, as opposed to other designs which utilized a barrel and bolt that slid in grooves machined in the frame. In the Browning design, the slide fitted into rails in the frame, and was integral with the bolt. The barrel rode in locking grooves machined into the interior of the slide, but attached to swinging links secured to the frame, one at the front and one at the rear. When the slide is forward (i.e., "in battery"), the length of the links holds the barrel up, locking it securely into matching grooves in the slide. Upon recoiling, the barrel and slide move backwards a short distance, locked together, until the arc of the links pulls the barrel downwards, disengaging it from the slide and halting its rearward motion. The barrel then stops moving, while the slide continues rearwards, extracting and ejecting the fired cartridge case and then returns forward, loading a fresh cartridge from the magazine. The barrel is caught, and moved forward with the slide, the camming action of the links lifting it again to lock into the matching grooves. This is identical to the modern style of short recoil action as developed for the later M1911, with the exception of employing both front and rear links, which causes the whole barrel to remain parallel to the slide as it drops out of the locking grooves. The M1911, and most other pistols since, found that it was only necessary to use a single rear link and locking grooves in the rear. When the slide retracts, only the rear of the barrel is dropped, causing it to tilt relative to the slide, while a fixed barrel bushing holds the front of the barrel in place when the slide is in battery, yet allows for movement of the slide and barrel. This approach was found to work perfectly well, and saved in complexity, cost of manufacture, as well as simplicity of assembly and disassembly.