Production shotgun-barrel lengths range from 14 inches (Mossberg’s Shockwave model, which technically is a “firearm,” not a shotgun) to 32 inches on shotguns made for clay-target games. So, what’s the ideal barrel length for home defense? Before answering, let’s discuss the trade-offs of short versus long barrels.
In general, shotguns with longer barrels pattern more uniformly and produce more velocity (which in turn translates to more energy downrange). But, longer barrels are more cumbersome to wield in the confines of a home. While pattern uniformity and velocity are most often subtle increases that you probably won’t even notice in all but the most extreme barrel lengths, you’ll certainly notice the ease with which an 18-inch-barrel shotgun can be maneuvered compared with a common 28-incher.
Academically, each extra inch of shotgun barrel adds approximately 10 to 15 fps to the load’s muzzle velocity; in terms of pattern uniformity, the longer, smoother forcing cone of a longer shotgun barrel typically leads to more consistent, uniform patterns as distances increase, but again, this is of little significance to home defenders. Therefore, I place more emphasis on maneuverability of the physical shotgun than I do on terminal performance (assuming both the gun and shotshell load are of adequate quality). For home-defense shotguns, I’d eliminate long barrels (anything longer than 26 inches) from my definition of ideal. I’d also eliminate very short barrels (anything shorter than 18 inches) for several reasons.
First, any shotgun with a barrel shorter than 18 inches is subject to National Firearms Act (NFA) regulations as a “Short Barreled Shotgun” (SBS). These include paying for a $200 tax stamp and personal registration (fingerprints, expanded background check, etc.) to purchase or transfer any such shotgun. “Firearms” like the aforementioned Shockwave are not covered by these restrictions, because they are manufactured without stocks.
Regardless, I believe a serious home-defense shotgun needs a legitimate, full-contour shoulder stock to help aim and control the gun while firing, so I rule out the Shockwave as ideal. But, even if shotguns with 14-inch barrels were readily available with shoulder stocks, I’d still not view them as ideal due to the fact that a shotgun’s magazine tube needs to be longer than the 14-inch barrel to hold more than five rounds. (These short guns are ideal for use in tight confines such as boats, trucks and police cruisers.) My thought is, if the shotgun’s mag tube is going to make the gun’s overall length longer, I might as well choose a barrel length long enough to match it, thereby realizing the longer barrel’s velocity gains and its decreases in noise, recoil (muzzle flip) and muzzle blast.
Over the years, I’ve trained with many defensive shotguns of various lengths, and I’ve found that 18- to 20-inch barrels provide an ideal balance of velocity/energy, maneuverability, pattern uniformity, muzzle-flip mitigation and magazine-tube capacity.
Mossberg’s 590A1 pump shotgun, for example, is available with a 20-inch barrel that holds eight rounds in its same-length magazine; the 18.5-inch-barrel version holds six rounds in the tubular magazine. Benelli’s M4 has an 18.5-inch barrel, but only holds five in the mag. Beretta’s excellent 1301 Tactical may be the best of both worlds, as it has an 18.5-inch barrel yet holds seven in the magazine. Its only downfall? It’s expensive. Moreover, Mossberg’s underappreciated 590M series wears an 18.5-inch barrel and has the capability to hold as many as 20 rounds in its detachable-box magazine.
Personally, I prefer a 20-inch barrel for at-home use because I like the extra rounds, and also because my house features a wide-open floor plan. But, an 18.5-inch tube might be best for your specific situation. Try one of each, then go with what works best for your home and home-defense scenario.
