FN 5.7 x 28 mm

[DocGKR]

Several papers have described the incredibly poor terminal performance of the 5.7 x 28 mm projectiles fired by the FN P90:

--Dahlstrom D, Powley K, and Gordon C: “Wound Profile of the FN Cartridge (SS 190) Fired from the FN P90 Submachine Gun". Wound Ballistic Review. 4(3):21-26; Spring 2000.
--Fackler M: "Errors & Omissions", Wound Ballistic Review. 1(1):46; Winter 1991.
--Fackler M: "More on the Bizarre Fabrique National P-90", Wound Ballistic Review. 3(1):44-45; 1997.
--FBI Academy Firearms Training Unit. FBI Handgun Ammunition Tests 1989-1995. Quantico, U.S. Department of Justice--Federal Bureau of Investigation.
--Hayes C: “Personal Defense Weapons—Answer in Search of a Question”, Wound Ballistic Review. 5(1):30-36; Spring 2001.
--Roberts G: “Preliminary Evaluation of the Terminal Performance of the 5.7 x 28 mm 23 Grain FMJ Bullet Fired by the New FN P-90 , Using 10% Ordnance Gelatin as a Tissue Simulant”, AFTE Journal. 30(2):326-329, Spring 1998.

The current 31 gr SS-190 FMJ bullet has nearly adequate penetration, but the wound resulting from this projectile has a relatively small permanent crush cavity, as well as an insignificant temporary stretch cavity. Although the 5.7 x 28 mm penetrates soft body armor, wounding potential is at best like a .22 LR or .22 Magnum. Even 9mm NATO FMJ makes a larger wound--and we are all aware of the awe inspiring incapacitation potential of M882 ball from the M9......

A few large U.S. LE agencies adopted 5.7 mm weapons--after being involved in several OIS incidents with P90's, 5.7 mm usage in these agencies plummeted as a result of the poor terminal performance.

It is all basic physics and physiology. Look at the surface areas in contact with tissue for 9 mm FMJ and JHP compared to 5.7 mm. When both are point forward, the 9 mm FMJ crushes more tissue than the 5.7 mm; for the short time that the 5.7 mm is at FULL yaw, it crushes a bit more tissue than the 9 mm FMJ. At no time does the 5.7 mm crush more tissue than the expanded 9 mm JHP--even when the 5.7 mm FMJ is at full yaw, an expanded 9 mm JHP crushes more tissue. The relatively small temporary cavities produced by both the 9 mm and 5.7 mm projectiles are not likely to cause significant injury to the majority of elastic structures of the body. As with any penetrating projectile, if either a 9 mm or 5.7 mm bullet is ideally placed to cause significant damage to the CNS or major cardiovascular organs, a fatal result is likely.



The P90 can definitely penetrate soft body armor, but then so can 9 mm AP rounds. The greater momentum of 9 mm bullets allow them to defeat vehicles and other intermediate barriers better than the 5.7 mm bullets. Standard 9 mm, .40 S&W, and .45 ACP JHP loads crush more tissue, offer ideal penetration, and are equally likely to not exit the opponent as the 5.7 mm. 5.56 mm and 6.8 mm weapons offer significantly superior terminal effects compared to 5.7 mm. Bottom line—what does the P90 offer that is not already available?