FN Five-seveN

American Handgunner, Jan, 2000 by Charles E. Petty

The barrel is also chrome moly steel. It is a two-piece design with a very interesting set of features. When you first look, it's obvious that the 4.9" long rifled barrel segment has two diameters. The main body is 0.61" OD which is reduced to 0.39" to fit into a sleeve that serves as a locking block.

But the really interesting thing is how the FN engineers managed the recoil spring. The aft end goes inside the locking block sleeve which serves to contain the back end of the recoil spring. The front end is contained within a tapered bushing that mates with a corresponding taper in the slide.

With the slide retracted it appears as if there is a small bushing, but that actually is a spring snap-ring that holds the spring captive. When you field strip the pistol, the entire barrel assembly comes out as one piece.

The frame has some pretty clever engineering too. Unlike many polymer frames that have steel rails molded on, this one has a rear assembly that contains a pair of rails along with parts of the trigger mechanism. The forward portion of the frame (the dust cover) has an integral rail that engages a slot cut in the slide.

This form of connection eliminates the need for a second set of slide rails in the frame, but would seem to be even more stable. Everywhere you look on the pistol is evidence of advanced engineering and thoughtful design.

The operating mechanism is described as "delayed blowback." With most blowback designs, the barrel is permanently affixed to the frame, but the Five-seveN has a slot that permits the barrel to move rearward with the slide about 0.1". A part of the locking block in the frame is spring loaded and bears upon the back of the barrel. The spring tension also provides some delay.

The trigger is double-action only and is among the worst I've ever seen. It isn't overly heavy, at 10 lbs., but it is abysmally long and creepy so that it feels a lot worse than it is. Actually, I'm sure that this is a deliberate design feature. FN informs me that a single-action trigger module will be available, but it was not designed to please gunwriters or target shooters, but to be safe in a combat environment.

Terminal Ballistics

The thought may have occurred to you that the cartridge is not proven on the street. When the .40 S&W was first announced, the naysayers used the very fact that it was new to condemn it out of hand. In so doing they were a bit shortsighted for nothing can be "proven on the street" until it's out on the street.

The Five-seveN surely may fail, but nobody really knows until it's tried. We rely on theory and laboratory testing since it isn't socially acceptable to do the kind of field testing that provides gut piles worth of information.

We were, however, able to test the Five-seveN by shooting into bare gelatin, gelatin covered with the FBI's standard "heavy clothing" and finally covered with IIA soft body armor.

For someone accustomed to full metal jacket bullets zipping through several feet of gelatin, the 5.7x28 was an eye-opener. We first fired at bare 10 percent gelatin and I fully expected the bullet to penetrate the entire length of the 12" block. It did not. Instead the bullet came to rest 7.75" into the block, but it had tracked upward about 2.5" from the point of entry. The permanent wound cavity was 2.75" in diameter.