No discussion about safeties on handguns would be complete without addressing the two that seem to cause the most controversy: grip safeties and magazine disconnect safeties. Although over the years several different pistol and revolver designs have utilized grip safeties, the primary one found in police service is the John Browning designed Colt Model 1911 and its clones.
Donald B. Bady, in his excellent and very detailed book, Colt Automatic Pistols (the second edition of which was published by Pioneer Press in 2000), reveals that the initial appearance of a grip safety on the military Colts was at the request of the U. S. Army, in its 1907 trials of the then experimental .45 caliber service pistol. Reports from the time indicate that the U. S. Cavalry representatives distrusted the safety of the proposed auto-loader during horse-back operations. They were concerned about cocking and decocking the pistol one-handed, with a live round in the chamber. One report stated that a horse had been accidentally shot when it stumbled while its rider had the pistol in hand. They wanted an automatic safety. This eventually evolved into the style we take for granted today on the 1911 model. Interestingly, there was no requirement that the 1907 model have a manual thumb safety, which also became the accepted standard for "cocked-and-locked" carry of the 1911 style pistol. However it evolved, the venerable 1911s are the most common representative of the grip safety idea. Of more recent design, the Springfield Armory XD and XDm pistols incorporate a version of the grip safety, which not only disables the trigger mechanism, but also locks the slide so that it cannot be manipulated unless the grip lever is depressed. The big question, however, is whether something that has been around for so long is really useful or necessary.
Many proponents of the 1911 style pistol don't seem to think so. For example, the late Col. Jeff Cooper, perhaps the foremost proponent of the superiority of the 1911 pistol as a combat and self-defense firearm, advocated pinning the grip safety down. If the safety wasn't fully engaged, it could disable the gun at a critical point in a gunfight. In fact, there are several different designs of grip safeties that incorporate bumps or ridges to ensure that the safety does indeed get fully depressed, even if your grasp of the gun is not perfect. This sometimes happens if your grip involves the thumbs forward or high thumbs style advocated by some instructors. Curling your gun hand thumb down brings the drumstick of your thumb into better contact with the backstrap of the gun, more positively depressing the safety.
Regardless of your grip preference, it seems to me that the grip safety has simply outlived its usefulness and serves no real purpose on a modern combat handgun. If anything, it is just one more thing to go wrong in the midst of a gunfight. That said, I still like my 1911s and my Springfield XDs and the presence of the grip safety has never been a problem for me. I just can't say it has ever been a help, either. Most unintentional discharges of 1911 style pistols occur during drawing or holstering. In either case, you already have a proper grip on the pistol, so the grip safety is deactivated. If you are careless enough to also have your finger on the trigger at that point, all that stands between you and a potential disaster is the manual thumb safety. If, of course, you remembered to engage it.
A grip safety seems designed primarily to prevent the user from accidentally firing a pistol with a relatively light, single action trigger pull, like the 1911. On the other hand, a magazine disconnect safety is more useful in preventing an unauthorized person from firing the pistol. When the magazine is removed from the gun, it prevents the gun from firing, even with a live round in the chamber. It does this regardless of the presence of any other safeties. As a result, it can actually be useful on a combat/defensive firearm. Pushing the magazine release button acts like an "off" switch, as the magazine falls or is removed from the gun.
There are a number of cases where law enforcement officers have been saved from death or injury because they intentionally dropped the magazine from their gun before losing control of the gun to an attacker. In at least one case that I know of, the attacker himself dropped the magazine out of a pistol while pushing on buttons, trying to figure out how to off-safe a Smith and Wesson pistol he had taken away from an officer. Indeed, Smith and Wesson has incorporated this feature in all of its semi-automatic pistols, beginning with the Model 39 back in the 1950s, and continuing through all the subsequent model and design changes used in police service since that time. At least, until now.
Their latest (and I think best) semi-auto service pistol, the M&P, makes the magazine disconnect available as an option, rather than a mandatory feature. I can remember many years ago that the Model 39, 59, and later the other variations of their all metal pistols were touted for the fact that a police officer could safely disable and store his pistol when he was off duty by simply removing the magazine. Still, he could immediately put it back in service by inserting the magazine. I wouldn't advocate leaving any gun with a live round in the chamber when it is being stored, regardless of the safety features. In that sense, however, it could be useful in an administrative law enforcement setting, such as checking your gun at a jail or at a courthouse, eliminating the need to remove and re-chamber a round.
Otherwise, there are at least two negatives about the magazine disconnect. The first is that the magazine release can accidentally be pressed while going about your daily routine. If this happens, your gun is disabled and you don't know it until you need it and the magazine isn’t there, or drops out as you draw the gun. The solution to that, of course, is to rearrange your gear so that doesn't happen. Regardless, you only have one round in the pipe if that happens even if the gun does not have a magazine disconnect, so it is important to always have a spare magazine handy to do an instant reload. Speaking of reloading, that is the other negative that is often mentioned in connection with these safeties. What happens if you have a round in the chamber, you’re in mid reload, and you need to fire that round?
Frankly, I think this is a non-issue. The argument started back in the days when advocates of the big bore 1911s were feeling challenged by the high capacity 9mm pistols, mainly the Browning Hi Power and the Smith and Wessons. Both of the nines had magazine disconnects and they were gaining fans. The 1911 crowd was trying to find anything they could to disparage their rivals. The big bore fans advocated shooting until there was one round left in the chamber, then reloading with the gun still hot. This was a faster reload (no slide manipulation) and kept one round ready, just in case. (Yes folks, this was actually taught back in the 1960s and 1970s.) Although this could work on the range, where counting to seven without the stress of someone shooting at you was do-able, it failed miserably under stress. In a real gunfight, the first clue most people have that they need to reload is when they realize that the slide is locked open. Experience has shown that beyond the first 3 or 4 shots, no one can keep accurate track of the number of rounds fired. So if the gun is locked open, it really doesn't matter if there is a magazine disconnect or not. What does matter is your ability to reload quickly and smoothly and get back in the fight.
What about the so-called tactical reload during the lull in the action we often hear about? You would have a live round available in the chamber during that process, just in case someone suddenly jumps out at you. Well, first of all, if you need that round you didn't do a very good job of identifying the lull. And even if you didn't choose wisely, how long does it take you to reload your gun anyway? Two, maybe three seconds? That's a pretty small window of opportunity for your opponent, wouldn't you say? If you are looking for a reason not to have a magazine disconnect, this isn't it. And whether your gun is so equipped or not, you should always have at least one spare magazine.
Frankly, I like the S&W M&P pistol because you can have it your way. You can have a thumb safety, or not. You can have a magazine disconnect, or not. I currently own two and both have the magazine disconnect. I honestly don't care whether they do or not. I have used S&W auto pistols for years and never had any problem with any of their safeties. But, like all professionals, you must be familiar with your tools. That, my brothers and sisters, is the bottom line. Whether your sidearm is a point-gun-pull-trigger firearm or has safeties galore, you need to be intimately familiar with how it works. If some feature bothers you by its presence or absence, either learn to love it or move on to a gun that works for you. Your life or the lives of others may well depend on how well you reflexively operate your weapon. There is no substitute for training and there is no substitute for having all of your brain cells front-and-center when danger threatens. When all else fails, your brain is your number one safety. Don't forget to keep your finger off the trigger until you are in the act of intentionally firing your gun. Think safe, act safe, stay safe.