Spall- aka The Big Splash

Bob warming up for the tests, he's in the zone right now...

What happens when you shoot a 62 grain bullet at approximately 2700 feet per second against a certified ballistic steel plate? You get one BIG SPLASH, not the fun type of splash either. You get the type of splash often referred to as spall.  The once whole bullet breaking up upon impacting a hard surface causing the round to turn into many - much smaller high velocity projectiles. 

---

Green grease paint helped indicate if any fragmentation struck the face or neck area

We wanted to know more so we set out to attempt a controlled series of tests.  What's that you say...people have been doing armor test on YouTube ever since Al Gore flipped the Internet switch on?  Hmm scrap that idea then.  Wait, what about doing a test on the very first thing the bullet strikes...the outside of the plate carrier which is holding all your cool guy gear….instead of the very last thing the bullet strikes i.e. the ballistic plate on the inside of the plate carrier.  Sounds good lets do it. 

---

Front Face Spall
These tests are more of a proof of concept.  We wanted to validate the probability of our initial ideas.   This test was not to validate the ballistic plate, but rather to document what happens when a bare metal plate is used with a typical plate carrier sans the spall guard or spall liner.

Additionally, we wanted to document the interaction between what we termed “first contact” by the rifle or pistol bullet when impacting any personal equipment i.e. anything hanging on the outside of the plate carrier such as pouches, magazines etc. Further we posed that the shooters arms, extended in a manner consistent with holding a rifle or pistol, would be at risk of receiving damage from the equipment being impacted by the projectile, small pieces of material, and bullet fragments could impact the forearms and inner portion of the upper arms causing serious and possibly life threatening injuries. 

Red lines are arteries greyish green lines are nerves.

Spall is defined as “Flakes of a material that are broken off a larger solid body”.  For this article I will use the term “Spall” to describe the fragmentation of the bullet when it strikes a ballistic plate thus causing the projectile to break into smaller parts.  There are better definitions and probably better words which could be used, however, we will stick with spall for this article as it is the most commonly used term when talking about front face splashback or fragmentation reflection.

The Hypothesis
A bare metal ballistic steel plate (no spall guard or spall liner) when shot with a high velocity rifle or pistol bullet, would be a danger to the wearer of the plate.  We went on to propose that the exposed arms (held out in a manner consistent with holding a rifle or pistol) as well as the lower legs (depending on body position / leg position) would be the most likely areas to sustain damage from spalling.

The Test Results
The first two video tests were done with a plate carrier containing the bare steel ballistic plate.  We observed the XP193 in the 1st video and the XM855 in the second video.  The first round struck the vest penetrating the outer material, the round shattering against the steel plate reflected small pieces of bullet fragmentation back out through the material.  

Reviewing the slow motion video and inspecting the ballistic gel, we found several small bullet fragments had penetrated less than a centimeter into the test dummies right arm.  Most of the reflected fragments which appeared to hit the ballistics gel in the video did not penetrate.  Those that did penetrate would not have been considered a life threatening wound.  We found upon inspecting the plate carrier that a large amount of bullet fragments were trapped in the hook and loop velcro around the cumerbun area.  The second round fired XM855 we did observe small fragments had impacted the face around the mouth as well as hitting the left lens of the safety glasses.

The third video shows a 7.62x39 round striking the front of the plate carrier which held a ballistic steel plate.  We observed small fragments from the spalling had penetrated the right arm as well as the left arm and noticeable fragments around the left cheek of the dummy.  The video shows a much more violent strike as compared to the  previous 5.56 rounds. The fragments in the gel ranged from a few centimeters to one inch.  The location of the fragment  on the left arm was in the lower forearm area.

The fourth video depicts a XP193 round striking the left ammo pouch low in the corner.  The strike was low enough that the round did not impact the ballistic steel plate, rather it penetrated the dummies lower stomach area.  No visible spalling or fragmentation occurred with this impact.  The magazine pouch tops were closed on this test.

The fifth video shows the magazine pouches with the pouch tops open depicting an emergency/speed reload magazine location.  We also wanted to see if having the magazine pouch open or closed would mitigate any fragmentation from spalling.  We observed the XP193 round striking the far right pouch containing a fully loaded steel 30rd magazine and a fully loaded polymer 30rd magazine behind it.  The round struck the steel magazine causing several of the rounds in the magazine to rupture and spill out powder into the bottom of the magazine pouch.  We observed a small puff of smoke as some of powder ignited and burnt off.  Upon removing the magazine we found that the top rounds still in the magazine had powder burn marks on them.  This would be consistent with our summation based on the video review that the cases ruptured spilling powder out and down into the bottom of the pouch then catching fire thus burning off the powder.  No observable fragments struck the arms or face of the dummy during this test.

The sixth video shows an XM855 round striking the middle pouch which contains 2 fully loaded 30 round magazines.  The round impacted the front magazine, breaking the upper portion of the feed lips off which then ejected all of the live rounds into the bottom of the magazine pouch.  No visible fragmentation contacted the ballistic gel or the face of the dummy.  Upon closer inspection the second magazine sustained substantial damage which would have prevented it from being used. 

The seventh video shows a XP193 round striking the left pistol magazine pouch.  Upon closer inspection we found a 3 inch penetration into the dummies right arm.  The penetration would have been in the area of mid-forearm.  This penetration location and depth would most likely lead to a significant and possibly life threatening wound.  

The eighth video shows a .45 ACP round striking the right pistol pouch and magazine.  We observed that significant fragments struck the chin and lens of the safety glasses.  The cuts in the skin on the face of the dummy are hard to quantify since the material is not similar to human tissue.  Several small pieces of plastic were stuck in the left gel block, and the depth was approximately 3 centimeters.  We observed several black plastic fragments on the right gel block, but the pieces did not penetrate any measurable distance.

The ninth video is just the bare metal certified ballistic plate held against the torso of the dummy by elastic bands.  The plate was shot with a 1oz Remington shotgun slug.  You can see the amount of energy transfer from the plate into the body of the dummy.  This one would be very interesting to do against equipment.  We had ran out of gear by this time so this test was done more to see the energy transfer and view how well the plate stood up to the slug.  Upon examination of the plate there was very little deformation of the strike face, no back face deformation at all. 

Key take aways-
We wanted to do a test that would document the effects of a high velocity projectile first contacting an individuals equipment.  We see from several of these videos that there is a significant amount of fragmentation occurring prior to the round entering and striking the bare steel ballistic plate. When we talk about spall liner or fragmentation mitigating material on the strike face of the ballistic steel plate, we often don’t take into consideration that the round has already impacted material on the front of the plate carrier causing fragmentation to occur. 

This test raises many other questions.  The test in and of itself was not designed to stand on its own.  After reviewing some of the findings we see the need to repeat the test with a more focused approach, and with controls in place which would allow for a more scientific comparison of fragmentation mitigation from ballistic steel plates with a spall liner and without a spall liner.  It is fair to say that in some instances it won't matter if the steel plate has a spall liner on it or not if the high velocity round strikes a piece of gear you are wearing on the outside of your plate carrier and disintegrates into hundreds of smaller high velocity projectiles; then the spall liner on the ballistic plate isn’t playing any role in mitigating the fragmentation.  What does that mean?  It means we want to do it again but the next time we will have a more ballistics gel, more cameras, and a list of new requirements which need to be tested. 

Conclusion
Spall or fragmentation can occur in numerous ways.  Focusing solely on one aspect of a piece of gear in a vacuum does not provide a holistic analysis of risks associated with a specific product.  I personally feel that if I choose to wear a ballistic steel plate it must have some type of proven spall mitigation built into the plate.  I also personally feel that even if I did have on a ballistic steel plate with a spall guard or spall liner/ or ceramic plate, the risk of catching high velocity projectile fragments caused by the round first impacting my equipment on the outside of the plate carrier- is a very real risk.  

Often times we get grumpy about the “eyes and ears” admonishment heard on every range -everywhere.  For me wearing Personal Protective Equipment has always been a love hate relationship.  PPE is never cool, it seems like PPE is always ill fitting and in my mind I never trusted it to “really work”.  Eyes are a must have if you are going to be an effective warrior / protector of your family.  Some of the fragments we observed embedded into the ballistics gel were only a few centimeters deep in the gel and the fragments were small enough to sit on the tip of an ink stick. However, if that same fragment hit your unprotected eyeball you might end up being completely combat ineffective from just a tiny fragment.  When you attend our Optics Enhance Night Fighting class, it becomes evident quickly that eye protection is your friend.  

Look at your equipment and understand the interaction between the gear you carry and high velocity rounds.  We found that every single round was stopped which made contact with the ballistic armor.  We also found that every single piece of gear which contacted a high velocity rifle or pistol round became unserviceable.  I’m not saying hide your gear, just keep in mind that if you are in a situation which doesn’t allow for equipment refit, then you might be hurting.  I usually wear a small backpack which contains different items many of which are specific to the task at hand.  I also have items that are always in the bag such as water, food, extra loaded magazines, and additional medical equipment.  

On the topic of medical,  take a look at the videos and imagine those are your arms sticking out.  Visualize the pipes which rundown the length of your arms carrying blood to and from your heart.  I wrote in a couple places above that the wound could possibly be life threatening.  We have some pretty big pipes that run from our upper trunk into our shoulder area and down our arms.  Consider how you would treat a wound on one or both arms which was a heavy bleeder.  Can you reach your tourniquet?  Is it accessible by both hands?  Can you deploy it with blood soaked fingers?  Your tourniquet isn’t still in that little plastic bag stuffed in an admin pouch located somewhere on your back side is it?

List of ammunition used:
PMC 5.56 55gr XP193 FMJ
Federal Lake City 62gr XM855
Wolf 7.62x39 123gr FMJ
PMC .45 ACP  185gr JHP
Remington 1oz shotgun slug 

Material used to simulate arms:
Clear Ballistics 
10% FBI Gel Block 16L X 6W x 6H
18 LBS Each

Plate carrier and pouches made with 500D Cordura material
Ballistic plate: level III certified AR500 ballistic steel
Troy 30 round Battlemag-impact resistant polymer AR magazine
30 round steel AR magazine
15 round 9mm KCI Glock magazines
Wiley X Romer II glasses with Shatterproof Selenite™ polycarbonate lenses