For the most part, the home defense shotgun category is dominated by a 12-gauge shotgun. It is the gold standard of shotgun versatility and what everyone uses. Thus, all the R&D goes, and new technology is applied, especially concerning defensive use. Because of this, the 20-gauge has some pretty significant problems when it comes to using them for defensive purposes. Wait, what? You heard me right. Hear me out.
20-Gauge Load Choice
We have talked about load selection for shotguns before. Regardless of what gets bandied about on the forums, YouTube, or whatever your favorite flavor of social media is, 00 buckshot is the king of defensive shotgun loads. It is where all the juice is. An argument can be made for #1 buckshot, and maybe even #4 buckshot, but the International Wound Ballistics Association had something to say about this over 20 years ago. It isn’t new info, and any shotgun instructor worth listening to pretty much says to use 00 buckshot because that is where the best performance is in terms of pattern size, reliability, and recoil.
If you are familiar with 20-gauge, you will know that there are not 00 buck loads in 20-gauge from the more reputable manufacturers. There are one or two #1 buck loads, but they are not very good. The pattern about like you would expect bottom shelf buckshot loads to the pattern. The usual buckshot loads for 20 gauge are either #2, #3, or #4 buckshot. We can get some decent loads with those shot sizes, with plated and buffered shots at least. The wad technology available in 12-gauge still isn’t there, but maybe for home defense ranges, we can go without. Careful choke selection will help us out a little too. However, even though they are still buckshot, all of those shot sizes are at best marginal options per the IWBA.
What About Lighter Recoil
Maybe we can do with just marginal performance from our load options if we can get enough of something else to justify the 20-gauge. The usual argument for the 20-gauge is that it is a smaller, lighter shotgun with less recoil. It sounds excellent. We could probably be okay with lackluster load options if we get a handier gun that works for more people. Unfortunately, the math on smaller + lighter does not equal less recoil. The 20-gauge gun still pushes close to the same payload at about the same muzzle velocity as a 12-gauge. The forces involved are close to the same. With the gun being lighter to boot, it ends up pretty much even in terms of recoil. Factor in that there are some really light, incredibly low recoil 12-gauge loads that don’t exist in 20-gauge, and the 12-gauge still ends up being the better choice for the recoil adverse.
So, what does the 20-gauge shotgun have going for it in the home defense role? Well, really nothing. That is ultimately the problem. It sounds like a good idea, but it just doesn’t work out that way. Load options are marginal; the less recoil thing doesn’t really pan out well enough to matter; the only thing left is just that it is a little smaller. The cost just isn’t worth the reward. In fact, there is an answer to the smaller, lighter, less recoil home defense shotgun question, but we will save that for another day.