Negative Opinion - Dr. Roberts

Go check the Terminal Effects forum on Tactical Forums

Doctor Roberts has a lot of real data...not hype

Here is a taste

Other than being able to perforate soft body armor, the 5.7 x 28 mm used in the FN P90, as well as the 4.6 x 30 mm fired from the HK MP7 cause wounds less incapacitating than those made by 9 mm FMJ fired from a pistol.

I have personally fired the 5.7 x 28 mm FN P-90; velocity, penetration, and tissue destruction is like a .17 Hornet--far less than we see with 75 gr TAP or 77 MK out of our M4’s. Winchester RA45T 230 gr JHP’s fired from our duty 1911’s crush more tissue and penetrate further than the 5.7 x 28 mm. Use of the 5.7 x 28 mm is a good way to ensure mission failure.

Several papers have described the incredibly poor terminal performance of 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.

--Roberts G: “Terminal Performance of the 5.7 x 28 mm 31 Grain SS-190 FMJ Bullet Fired by the FN P-90 in 10% Ordnance Gelatin.”, AFTE Journal. In Press.

The early 5.7 x 28 mm 23 gr FMJ bullet fired by the FN P-90 had insufficient penetration for law enforcement and military use. 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......

Numerous other projectiles commonly used for law enforcement and military special operations applications, such as a good 9mm, .40 S&W, or .45 ACP JHP, the better 5.56 x 45 mm BTHP/JSP loads, as well as 12 gauge shotgun slugs and 00 buckshot, all provide better penetration, crush more tissue, and have far greater potential to reliably physiologically incapacitate an aggressor than the 5.7 x 28 mm 31 gr SS-190 FMJ bullet fired by the FN P-90. Law enforcement agencies and military special operations units are strongly urged to avoid adoption of this weapon system.

FN P90 Misc

Manufacturer: Fabrique National, Herstal, Belgium
Type: Selective fire submachine gun
Caliber: 5.7X28mm SS 190
Operation: Blowback
Weight: 6.6 lbs., loaded
Overall Length: 19.7 inches
Barrel Length: 9.5 inches
Magazine Capacity: 50 rounds
Rate of Fire: 200 rpm on automatic
Muzzle Velocity: 2,330 fps
Effective Range: 200 meters

The Weapon

The FN P90 submachine gun, along with the FiveseveN pistol, were designed to give military personnel a system of weapons that were smaller than conventional rifles and carbines, but retained the ability to penetrate soft armor and combat helmets. The P90 is largely constructed of polymers, which contribute to its light weight and unique profile. At less than twenty inches in overall length, the weapon is compact and maneuverable, with controls and straight down ejection that make it entirely
ambidextrous.

A revolutionary feature of the P90 is the see-through, double column, polymer magazine. The magazine rests atop the weapon, parallel to the barrel, as can be seen in the above picture. The cartridges are actually held perpendicular to the barrel's axis, bullets pointing toward the operator's left, and each round is rotated 90 degrees for chambering. In spite of the compactness of the design, the magazine holds 50 rounds of 5.7mm ammunition.

This submachine gun is equipped with a 1X optical sighting system with low light reticle, and has iron sights on each side of the scope, for left- or right-handed shooters. There is an optional built-in laser sight, and a rail to mount flashlights or lasers on either side of the optical sight. A brass catcher is available that snaps onto the ejection port at the bottom of the weapon. It has a capacity of 100 empty cases.

The P90 can be fitted with a suppressor that is 7.9 inches long and 1.6 inches in diameter. Constructed of steel and aluminum, it weighs only 0.88 pounds. When used in conjunction with the
Sb 193 subsonic ammunition, a 30 db reduction in sound is claimed.

The Ammunition

The 5.7X28mm cartridge is something of an intermediate between the 5.56X45mm and 9X19mm NATO rounds. This diminutive round is only 1.6 inches in overall length, with a case diameter that is slightly more than half that of the 9mm. The ammunition is only about half the weight of the 9mm as well- a mere 93 grains per ball round. Recoil impulse is on par with .22 Rimfire rounds, even with a chamber pressure that exceeds 49,000 lbs./psi.

There are currently five types of ammunition available in 5.7X28mm: ball, tracer, subsonic, blank, and dummy. The SS 190 ball cartridge is topped with a 31 gr. steel-jacketed, dual core projectile. A steel penetrator is located in the tip of the bullet, as in the 5.56mm SS 109 projectile, but the aft portion is filled with aluminum, instead of the more conventional lead. Muzzle velocity is about 2,330 feet per second out of the P90 SMG, which results in a muzzle energy of about 374 ft-lbs.

The SS 190 bullet was designed to penetrate up to Level IIIA soft body armor. Testing indicates that it will barely penetrate a 12 inch block of ballistic gelatin, and will penetrate less than 10 inches of gelatin after defeating a ballistic vest. Though some 15 countries use the P90 and FiveseveN systems, the weapon has apparently been used in actual combat only once: six suppressed P90's were used by Peruvian forces during the raid on the Japanese embassy. Unfortunately, results are classified.

Enter the IWBA

The January, 2000, issue of the American Rifleman magazine contains a letter written by Dr. Martin L. Fackler, President of the International Wound Ballistics Association. In his correspondence, Dr. Fackler blasts the magazine for publishing a previous article which insinuated that the 31 gr. SS 190 projectile produces a wound cavity similar to the 62 gr. SS 109 bullet used in the M16A2. Calling such a comparison "an absurd exaggeration," he noted that the P90 bullet does not match the "wounding capacity of a well-designed, expanding 9mm handgun bullet." The doctor further stated that the 5.7mm projectile is about equal to the .22 WMR in actual wound potential.

tangofox's Take

For better or worse, this author believes the P90 to be a harbinger of things to come. Polymers, bullpup stocks, small-caliber ammunition, optical sights, and ambidextrous operation are here and here to stay. Say goodbye to wood, leather, conventional layout, and iron sights (except as backups) for military arms of the future. Illuminated reticles are becoming the rule, rather than the exception, and this is a good thing. At least most countries are adopting weapons for the next generation that do not require batteries, unlike the United States.

In an admittedly apples and oranges comparison, the muzzle energy of the 5.7mm ball round (374 ft-lbs.) is about equal to that of the 9mm NATO and .45 ACP. Since projectile weight and muzzle velocity for the Sb 193 subsonic round were not available, the author used the 31 gr. weight of the SS 190 bullet and the arbitrary assignment of 1000 fps as a (barely) subsonic muzzle velocity to obtain a muzzle energy of only 68.9 ft-lbs.! A 40 gr. bullet would raise energy by 20 foot pounds, but that is still less than a .22 Long Rifle when fired from a rifle-length barrel.

Is the little 5.7X28mm round up to the task? That is the $64,000 question. There are wildly differing accounts of the cartridge's wounding potential. One would think that if the P90 had been a great success in the Japanese Embassy raid, Fabrique National would be trumpeting the results to generate more sales. But, the world must wait until the weapon sees more combat use to see if this is a revolution in small arms ammunition or a flash in the pan.

Fackler letter to the NRA regarding FN's 5.7mm (Negative Opinion)

...reprint this letter (American Rifleman, Jan 2000, p. 4) from Dr. Marvin Fackler:

"The article 'FN's FiveseveN System (No.v/Dec. 1999 p.40) seriously misrepresents the wounding capacity of the 31-gr. P90 bullet. Claiming it "produces a wound cavity that is similar to that of the 5.56 mm NATO ammunition is an absurd exaggeration. The 31-gr. P90 bullet has only half the weight of the M16A2 bullet - and its velocity is about 1000 f.p.s. less. (The reference was intended to convey that it is an FMJ design, not that it has equal energy and wounding characteristics to the 5.56x45 mm cartridge. - The Eds).

The amount of tissue disruption propduced by the P90 bullet is less than one-third of that produced by a well-designed expanding 9x19mm handgun bullet. And the P90 produces a temporary cavity of only about 8cm diameter - smaller than that of an expanding 9mm handgun bullet. Most of the P90's bullet's wounding potential is wasted in producing a temporary cavity that is too small to be a reliable wounding mechanism. The P90 bullet doesn't even come close to matching the wounding capacity of a well-designed, expanding 9mm handgun bullet.

The light recoil of the P90 should hardly come as a surprise: The momentum and kinetic energy of its bullets are only about half that of the .22 Hornet bullet. The P90 bullet's wounding potential is about equal to that of the .22 WMR bullet. The laws of physics cannot be denied - minimal recoil is inconsistent with maximal tissue disruption.

For the military, where any wound is often all that is required to cause an enemy soldier to leave the battlefield, perhaps this tiny P90 bullet is OK. Law enforcement officers are often faced with armed violent criminals at close range. In that scenario, a bullet capable of disrupting a significant amount of tissue is needed: One must incapacitate a criminal, a minor wound will not suffice. By no stretch of the imagination is the P90 bullet adequate for that task.

References for further reading in the Wound Ballistics Review are: Vol. 3, No. 3, 1998 (pp. 36-37) 'Corrections on the Wound Ballistics of the current FN P90 bullet'; Vol. 3, No. 1, 1997 (pp. 44-45) "more on the bizarre FN P90'; and Vol. 1., No. 1, 1991 (p. 46) 'Description of the first generation P90.' These may be obtained from the IWBA by calling (310) 640-6065, or its website at www.IWBA.com.

Marvin L. Fackler, MD, FACS,
President, Int'l Wound Ballistics Ass'n.