Many people hear about using 00 and 000 buckshot for home defense purposes. Inside the home 00 and 000 buckshot has a bit more ability to penetrate walls than you may realize and much than you should be comfortable with if you have neighbors that live close or other persons in your household, such as children. Likewise, if you are not careful and use shot that is too small it may be too light to penetrate deep enough to stop an attacker. Understanding the proper ammo to use in your shotgun will help you avoid unnecessary problems.
My preference in shotgun ammo for home defense is #4 Buckshot. Here are some comparisons to help you make your own decision about which ammo you should use.
Comparison of Shotgun Ammo
000 Buckshot is .36" in diameter and weighs about 71 grains per pellet. In a 3" shell you have 9 to 10 pellets and in a 2 3/4" shell you usually have 8 pellets. Velocity is around 1325 fps (feet per second) for the 2 3/4" shells and a bit slower for the 3" shells.
00 Buckshot is .33" in diameter and weighs about 60.5 grains each. 3" shells hold approximately 15 pellets and 2 3/4" shells hold around 12 pellets. Velocity is approximately 1250 fps.
#1 Buckshot is .30" in diameter and weighs 40.5 grains each. There are approximately 24 pellets in the 3" shells, and the pellet count varies from 16 to 20 in the 2 3/4" shells. Velocity also varies from 1075 fps for the 3" shells to 1250 fps for the 2 3/4" shells.
#4 Buckshot is .24" in diameter and weighs just a little over 20 grains each. There are approximately 40 pellets in 3" shells and the pellet count varies from 27-34 in 2 3/4" shells. This depends on whether or not the shot is buffered. Velocity speed varies anywhere from 1250 fps to 1325 fps.
#4 Birdshot is .13" in diameter and weighs a mere 3.2 grains each. In a 2 3/4" shell with a 1 5/8 ounce shot charge, there are 221 pellets with a velocity of 1250 fps.
The velocity is not the most important variable in most cases. Pellet weight and pellet count are actually more important considerations. At 3.2 grains, the #4 birdshot does not weigh as much as a simple playing card. Even at 1250 fps, it lacks the mass necessary to stop an intruder. The sole advantage is in the pellet count. That many pellets will make a large, shallow, nasty wound but the intruder is still liable to survive.
In considering the other loads, you have only 8 or 10 of the 000 Buckshot pellets, but they weigh 71 grains each, that is the same weight as a .32 ACP's FMJ bullet, and it is moving faster than a .32 ACP throws its single bullet. With the combination of weight and velocity, 000 Buckshot will penetrate any drywall and any non-masonry exterior wall with relative ease, and thereby possibly endangering your neighbors. Being only 10 grains lighter, 00 buckshot shares many of the same drawbacks as 000 Buck (low pellet count and high penetration).
With the #1 and #4 Buckshot loads, we cover the range of .22 rimfire bullet weights. The #1 is the same weight as many .22 WMR bullets, and the #4 is just a little lighter than the lightest .22 LR bullets. Both of these buckshot loads are zipping along at speeds near .22 WMR velocities, but with a much bigger payload. That weight and velocity gives you enough penetration to stop intruders and minimizes the effects of wall penetration.
There is also the difference in recoil and your ability to control your shotgun. This can also be of importance to those persons of smaller stature who may be able to handle the recoil more efficiently and with fewer problems. Being able to maintain greater control of your shotgun due to less recoil may allow you to get off a second shot if you somehow miss with the first. Which is a distinct and real possibility in the middle of the night and you are still half asleep. The ability to perhaps get off a second shot can sometimes make a significant difference in the outcome between you and an intruder.
And don’t let anyone tell you that you don't have to aim a shotgun. At distances inside your home, you will probably have less than 30 feet as a maximum range. The shot spread will usually be less than 10" even with an open bore. It is quite easy to miss a man-sized target at that range when you only have 10 to 15 pellets in your pattern. Then you will still have to worry about who or what is on the other side of the wall that your pellets strike, such as children who may be sleeping in another room.
With the lighter weight and higher pellet count of the #1 and #4 Buckshot, you have a lot more pellets in that 10" pattern and more chances to strike a crippling if not fatal blow to an intruder while not having to worry as much about the after effects of over penetration.
Ultimately you will need to make your own choice and decide for yourself which load you prefer to use for home defense. Your skill and abilities with your shotgun, the number of persons in your household, and the proximity of neighbors should all be important factors in making a decision.
Staying above the water line!