Even Browning's semi auto shotgun had to be first produced by FN.
Incorrect. It
was first produced by FN, but it did not
have to have been. Browning was in the outer office, with his prototype shotgun, waiting to meet with the Remington VP when the VP had a heart attack and died right there. At that point, figuring things at Remington were going to be "up in the air" for a while, Browning took his gun to FN, with whom he had dealings before, and the rest is history. Browning first went to Winchester, who wasn't interested, then went to Remington with his Auto5 shotgun, then went to FN. Since Remington later produced the shotgun when they got the chance, its likely they would have adopted it before FN, but the guy who would have made that decision died, minutes before meeting Browning.
Many things about the use of handguns in armies come over from their use of long guns. (Think for a bit on the role the magazine cut off played in bolt action military rifles.
I understand your general point, but I think you are confused about what a magazine cutoff is, and its intended use. It is in NO WAY comparable to a magazine disconnect in a pistol. They do not do the same things, and the concepts behind them are totally different. The only thing they have in common is the word "magazine" in their name.
A magazine cutoff "cuts off" the magazine from FEEDING into the chamber. The gun will fire the chambered round normally. The cutoff is an "active" thing, it only goes on when the user switches it ON and stays on until the user switches it off.
It is a result of US military thinking from the early repeating rifle era. In essence, the idea was that the soldier loaded the mag, cut it off, and then loaded and fired single aimed rounds, "saving" the magazine capacity for emergency use, such as repelling an assault. The brass wanted that firepower kept in reserve, as much as possible. Events later proved the flaws in this idea, and the cutoff idea was dropped. You find the cutoff on Krags and the 1903 Springfield, You don't see it on later arms, and you don't see it on other nations rifles of that period, generally.
There is one exception I know of, and that is on the Browning A5 shotgun.
Same mechanical result, stops rounds feeding from the magazine, but for a different reason than the military cutoff. On the shotgun, it cuts off the feed, so that the shooter can unload the chamber and reload it with a different shell, without having to work the action to empty the magazine, THEN be able to put a different size shot round into the chamber. Rather a slick idea, actually. Say you've got the magazine full of #6 for ducks and a goose shows up and you want #2, you can hit the cutoff, then swap out the chambered #6 shell easily. Also the gun absolutely WILL fire the chambered round with the cutoff ON (activated)
Magazine disconnects are different. They "disconnect" the firing mechanism so the gun will not fire unless the magazine (body) is in the proper place.
Big difference.
(The 1st and 2 variations of the Colt M1903 did not have mag disconnects. The later variations did have them.)
I thought this was incorrect, and had to do some digging and in the process learned some things I had not previously known. It is correct. The Colt pocket .25 (not the Browning design) and both the .32 and .380 pocket guns did get magazine disconnectors, starting about 1926. Guns made before then don't have them guns made after do. Production of all those guns ended in 1941 with WWII. After the war, Colt did not resume production of those guns and nothing else Colt made had a magazine disconnect.
It instantly reminds the soldier, by not firing, that the gun needs a mag in it to be useful.
Partially disagree. All not firing "reminds" the soldier of is that the gun didn't fire. The why, he has to figure out on his own, and that is a training issue.
In the real world one could as easily eject a mag from a pistol without a disconnect as from one with it.
This is not 100% accurate. It depends on the guns. The Browning High Powers I've had have a degree of drag on the magazine from the disconnect. A fully loaded mag would usually fall free. A partially loaded mag would not always fall free of the frame, and empty mags almost never did, just popping down a little bit and being retained in the grip frame due to the drag from the disconnect on them. A Coit 1911A1 by contrast (no mag disconnect) you hit the button (slide closed) the magazine "jumps" out. Slide open it falls free. (and if it doesn't its defective
)
And Please, do not use the internet slogan "The best safety is the one between your ears".
Why not? Not only is it true, it's basic firearm safety, and has been taught for at least century or two before there was an Internet. The fact that some people don't use that between the ears safety well enough or often enough does not invalidate the idea, and in fact emphasizes why we should keep teaching and repeating it!
What current models of pistol, intended for the military or police market (duty pistols) have a magazine disconnect?
Pistols intended for the personal defense market sometimes still do have magazine disconnects. The civilian personal defense market includes a lot of people who are not well trained firearms enthusiasts, and are never going to be. For those people I can see a benefit to a pistol with a magazine disconnect. HOWEVER, there is also a dangerous drawback, and its not with the gun, but with the users. Simply put, since all pistols do not work the same, if you learn to rely on a magazine disconnect, and then get a gun without one, without understanding the difference there is a significant risk.
Magazine disconnects? you like em? Fine! Have all you want. I don't like them, and will avoid them if practical, but having one isn't a deal breaker for me.