Originally Posted by LiveSteam
Very Interesting. Never heard of the 5.7x28 before
The 5.7x28 is a relatively new round, compared to the 9mm and .45acp. One of the features of the 5.7x28 is the ability to defeat ballistic armor, even at longer distances, using what is called SS190 rounds (steel core.) The .45acp and the 9mm weren't designed with that purpose in mind, although if you're close enough with a hot load and a FMJ round, you can probably defeat ballistic armor with either of them as well.
The velocity of the 5.7 is much faster than the hottest 9mm loads, and close to double that of the hottest .45acp out of the same barrel length due to the light weight of the bullet, which is basically a rifle round. Makes a nice loud noise, kinda like a .357 magnum, but it kicks like a .22 or .25. Very controllable, and very accurate with a steady finger out to distances where the 9mm and the .45acp would just be digging in the dirt.
The bottleneck design would probably result in more reliable feeding; I haven't had any feed problems yet, after 400 rounds, even while breaking it in. The overall compactness of the round (28mm in length) makes it practical to use in an actual pistol-sized frame, and still have decent velocity. The size of the round also allows a capacity of 20 rounds in a single magazine, whereas the 9mm would have maybe 15, and the .45acp would have maybe 8 or 9 rounds in a similarly-sized pistol
tac team I was on in the late 90s almost went to a pistol like that when we switched from MP5s to the Micro Galil, couldn't get the higher ups to sign off on it, wanted to stay uniform across the board with 9mm pistol rounds for all the officers. I forget if it was the FNH though.
actually I think it was the company trying to sell us on the p90, matching rounds for rifle and pistols. So I guess it was the FN