Sunday, March 18, 2012

SIM-TEST Terminal Ballistics Test Media

Last month, I mentioned that I was going to get my hands on a 60 lb. box of SIM-TEST ballistics test media so I could use it to evaluate the terminal performance of my favorite ammo in some of my favorite mouse guns.  I really struggled with the decision to pony up the money for this stuff because it's really pretty expensive stuff and just the shipping was a substantial cost.  Ideally, I wanted to get my bullet box up and running, but that hasn't worked out well so far. 

SIM-TEST is really some neat stuff.  Rather than interpret the sales information from Corbin's website, I'll just show you the information that reeled me in as a customer.  This all comes from the Corbin website.

"Corbin SIM-TESTtm ballistic test media is a stable, animal-protein based "simulated tissue" for consistent bullet performance tests. The material is a very close match to muscle tissue in density and consistency. The density is 1.3 gm/cc. (Density can be adjusted by controlling water content.) The major advantages over ballistic gel is stability at room temperature, and nearly unlimited re-use (melt and re-cast), which makes it a long term investment instead of a one-use throw-away.

You may have seen episodes of "CSI" or "Myth Busters", where entire human torsos or body parts were molded from Sim-Test and used in forensic experiments. Sim-test has also been used by Naval Research Labs, Department of Energy, COSI, John Hopkins University, and other ballistic labs, medical research facilities, and even hypodermic needle testing and protective body armor and helmet testing. Inserting acceleration gauges and impact sensors directly into castings of the material, which melts at about 140-deg. F, allows precision simulation and testing of the effects of impacts through protective clothing. SIM-TESTtm has these advantages over wet newspaper, water, clay, conventional ballistic gelatin, and other test materials commonly used as a bullet expansion medium:
  1. Stable at room temperature.
    Unlike gelatin, water-soaked materials, or water-based clay, SIM-TESTtm remains the consistency of animal muscle tissue without refrigeration.
  2. Ready to use without mixing.
    SIM-TESTtm does not require mixing, so it maintains the same consistent density from test to test.
  3. No refrigeration required.
    SIM-TESTtm can be used without refrigeration, unlike water-based gels which spoil or need to be refrigerated to consistent temperature to maintain their density from shot to shot. The testing can be done in the field. (Store in a cool, dry area for up to one year)
  4. Re-usable, re-castable.
    SIM-TESTtm can easily be melted and re-cast using a water bath boiler pan, letting one "brick" cool while others are being used. Quickly sets up for another shot. Fragments can be added back to the mould, and the melted material strained to remove bullet fragments.
  5. Water soluble, easy clean-up.
    SIM-TESTtm dissolves completely in hot water. It can be diluted and used in tanks as a variable density tissue simulant.
  6. Close simulation of actual tissue.
    SIM-TESTtm is an excellent match to the density and elasticity of live animal muscle tissue, providing a superior simulation for bullet testing and forensics."
So now I'm thinking if it's good enough for "Myth Busters", it's good enough for me.  Plus it's reusable, temperature stable, and all that other good stuff.

In use, I wanted to be able to use SIM-TEST that had been diluted with water to match the density of traditional ballistics gelatine.  Seemed pretty straight forward.  Just add some water to decrease the density.  In reality, it's a bit more difficult than that.  I shot a video of what it takes to dilute the raw SIM-TEST into a density similar to ballistics gel.

So was all that work worth it?  You bet it was.  I didn't get the mix correct on this specific batch.  I think it was a bit too soft.  I recently purchased this awesome new BB gun that said it would launch BBs at 620 fps.  I needed a BB gun that could shoot bbs at about 600 fps so I could validate that my SIM-TEST blocks were close to the published FBI Ballistics Gel standards of: "Calibration of ballistic gelatin is verified by firing a .177 steel BB at 590 feet per second (fps), plus or minus 15 fps, into the gelatin, resulting in 8.5 centimeters (cm), plus or minus 1 cm, penetration (2.95" – 3.74")."  I probably wasted about 45 minutes shooting the BB gun over the chronograph.  One reason was it was really fun.  The second reason was that even at maximum pumps (10) the highest velocity I could get was 503 fps.  I either got ripped off by the folks at Crosman, or the gun needs more break in before hitting the top side of it's velocity potential.  I still used the blocks and they still caught the bullets.  My previous batch was firmer and held together better at the range today.

I took four blocks of SIM-TEST out to the range today and tested 4 different 380 ammo brands.  I'm still working on the video edits, but should have those results published later this week.

No comments:

Post a Comment