Operation is by means of sliding a fore-end that travels back and forth under the barrel and parallel to the bore axis. Action bars cycle the bolt. Often nicknamed a trombone- or pump-action. The receiver may be stressed or unstressed, with the latter the most popular.
Advantages: Reliable operation; inexpensive to manufacture; popular type offered in many brands; can handle high-pressure cartridges.
Disadvantages: Dual operating rods needed to avoid binding; may prove too noisy in some scenarios; operation difficult for some shooters.
Pump-action shotguns are a very popular choice for home defense. Click here to read an article from our friends at Shooting Illustrated on the subject!