As you can see from the above picture .45 ACP, .357 Sig, and .40 S&W all have about the same terminal ballistics or stopping power at short range. The .357 Sig and 10mm have much better ballistics at longer ranges due to their higher velocity.
Nothing can beat a 12 gauge shotgun with 00 buck though. Each pellet from a 12 gauge is equivalent to an AK at 100 yards. The spread of a shotgun is a lot less than what most people realize. The Box-O-Truth shows a 2 1/2″ spread from 12 feet.
.223, 55GR. Commercial load
.38 S&W………..153.5 dB
.357 Magnum…….164.3 dB
.45 ACP…………..157.0 dB
.45 COLT…………154.7 dB
Ironically a 9mm handgun is much louder than a shotgun with a typical 26″ skeet barrel. Also, most people don’t know that shotguns can be suppressed.
Magazine Capacity & Adaptability
A Sig .357 can often be converted to a .40 S&W with a simple barrel change. No magazine change is required. A Glock 33 can shoot .40 S&W and .357 Sig and 9mm with barrel and magazine changes. For reliability an extractor change is often necessary to convert a .40 to a 9mm but the cost is often justified due to ammo costs. The difference in price in ammo can be notable, especially since the military uses so much 9 mm you can get it as surplus.
Nothing can beat the reliability of a revolver. Smith & Wesson 442 “Airweight” is an ideal self defense handgun because it is small, reliable, and the hammer is highly unlikely to get caught on something.
Magazine springs wear out from compression and decompression. It’s the changing of states that causes wear and tear on the springs. That being said you should load a magazine and let it rest for 5 years. Make sure you test it every once in a while.
A 9mm is often described as a slap while the .45 ACP is described as a push. Practice with both and figure out which one is easier for you to handle.
Practice shooting with a .22. Besides a .22 in the hands of a marksman is far more potent than a big-bore rifle in the hands of a novice. Read the 4 rules on safety.
Dogs & Laws
Dog ownership entails daily feeding and walking, intermittent medical care, etc. They are a great alarm but are by no means cheaper or less maintenance than a shotgun. Some States require that to use deadly force you have to announce that you are armed and lock yourself in a room, and the intruder has to be trying to get to you for self defense to be considered. That is an extreme, but it does still exist. Legal fees can be expensive….