Brass Fetcher Ballistic Testing


“They laughed when I pulled out my P90 but…”


(Courtesy: Oleg Volk)

Defense through Science.

         The first recorded Personal Defense Weapon was the German Luger, issued with a shoulder stock, in World War one.  Accompanying the astonishingly rapid advances made during that era in military hardware came an increasing tendency among planners to make warfare a ‘game of numbers.’  Specifically, the application of statistics and probability to small arms design and conceptualization began in its infancy during this time period. 


         Personal Defense Weapons, PDWs, are intended to be used by personnel whose role does not make them likely to need a firearm with any great frequency.  Such firearms are lightweight, small in size and hold a large number of cartridges.  They differ from submachineguns in that PDWs typically offer lower recoil (and often lower terminal effectiveness against a human attacker), greater armor piercing capability (with ammunition designed to penetrate soft body armor) and better controllability during fully automatic fire.  Modern implementations of this concept include the Heckler & Koch MP7 and the FN P90.

         High-velocity projectiles such as bullets have two distinct wounding mechanisms: tumbling and expansion.  Military rifle bullets will tumble after traveling some distance into the gelatin block or the body of a human attacker.  The wounding can be dramatic if the tumble comes quickly enough.  Jacketed hollowpoints intended for use in handguns will expand within the first two diameters of penetration and will rapidly decelerate within the target.  This is what is desired when engaging structures of the body that offer narrow shotlines such as hits to the arms and legs.  In order to be effective a Jacketed Hollowpoint must be capable of expanding and penetrating deep into the chest cavity as well.  If any expansion takes place, this necessitates firing a cartridge in the 9mm Luger or larger kinetic energy ‘ballpark.’  Smaller cartridges typically fire bullets that are not heavy enough to penetrate deeply to reach the vital organs.


Examples of this function are represented graphically below.

How the 5.7mm FMJ bullet compares to a 9mm Luger handgun

Optimal soft tissue FMJ performance.

Optimal soft tissue JHP performance.

         The wounding efficiency of any bullet depends on how much kinetic energy the bullet possesses at the time of impact and the depth at which the bullet experiences maximum fluid drag (“transfers maximum kinetic energy” to use popular parlance.)  Bullets that tumble at some depth in ballistic gelatin travel through the shallow non-vital tissues and causes great destruction at the deeper depths once tumbling and fragmentation occur.

By far the most popular PDW cartridge is the 5.7x28mm.  It is the only PDW type firearm that is commonly available to civilians where gun ownership is legal.  As such, the below graph is an analysis of the wounding potential of an Elite Ammunition S4M (hot-loaded 28gr FN SS-195 projectile) compared to the terminal performance of a 9mm Hornady XTP JHP shot from 9mm handgun.  Both bullets expand upon impact with the gelatin so the wounding mechanisms can be considered to be the same.  We see here that the typical expanding 5.7mm projectile does less damage than a standard pressure 9mm Luger JHP.  

How the 5.7mm expanding bullet compares to a

9mm Luger handgun firing JHP ammunition

         Despite the anti-gun segment of the media and their fear mongering to the contrary, commercial 5.7x28mm ammunition is not inherently armor piercing.


         To the right we tested the commercial FN ammunition against a new NIJ III-A vest.  All were unable to penetrate the vest or cause backface deformation sufficient to fail the vest in NIJ testing.

The SS-190 round from FN is armor piercing (soft body armor) and it is a fantastic design.  I highly recommend it if you are able to obtain some.

         As of this writing in early 2014, expectations of a completely peaceful resolution to the world economic crises and the social problems faced in most industrialized countries is myopic at best or demonstrates a complete lack of acceptance of human behavior and history.  Events such as the Great Depression and the World War that ended it serve as modern reminders of the potential for severe hardship. 


         Reading peoples online comments regarding ‘SHTF’ and nonsense about Zombies has convinced me that more than a few people think that they will be fighting on their own terms in a defensive situation.  That is the ideal goal, but “Ideal” is a long ways from here.  The time that 2-3 males tried to break down my apartment door (unknown to me at the time, the tenant the month before was evicted for drug dealing), they did not give me the courtesy of advanced notice of their plans.  If it were not for my dog barking they would have been in the door in 4 kicks and all over me before I knew what was going on (at 3am.)  Putting myself in the shoes of one of ’the horde’ or some other such evil character, I would make every effort to maintain the element of surprise on the people I was attacking.  I would not expect people who are criminals during normal times to cut any slack now or at any point in the future.


         This is where the PDW comes in.  I highly recommend that you buy a FN PS90 and if possible, pay the ATF tax stamp to get the barrel cut to the length of the P90.  Buy a sling for this weapon.  What is the point of having a gun small enough to carry anywhere if you don’t have the sling with which to carry it?  A PDW is lighter than the lightest AR-15 carbines, shorter and make less noise when fired inside of a structure or vehicle.  This is important in enclosed spaces because the pressure coming out of the muzzle can greatly disturb you or injure a partner whose ear got too close to the muzzle at the time of firing. 


         Real SHTF situations in the recent past seem to involve waiting, eating, sleeping and other mundane tasks much more than they do active combat with attacking hordes of refugees.  Be that as it may, the pistol-like portability of the PDW gives you the option to have the accuracy of a shoulder weapon, stopping power of a handgun and the capacity and range of a rifle while you are driving your car, fixing something in the field, using the restroom and so on.  They will attack on their terms, not yours.  Meet that force with righteous indignation and diligent preparation.

See how well this caliber stacks up against the FBI performance requirement of expansion and 12.0” or deeper penetration depth.

Heavy Clothing is placed in front of the gelatin block to simulate an attacker wearing winter clothing.

Simulating a shot into an attackers chest then through an interior wall and into a gelatin block on the other side.

See how well this caliber stacks up in military-standard performance evaluations.

So cheap and available,

everyone can own it now.