Better And Better

If you don't draw yours, I won't draw mine. A police officer, working in the small town that he lives in, focusing on family and shooting and coffee, and occasionally putting some people in jail.

Saturday, May 12, 2007

Blood spatter practical excercises

For my blood spatter class, my lab partner Eric and I decided that no practical exercise would be complete without some gunplay. Others smeared, splashed, and stamped blood; we decided to create high velocity impact spatter (HVIS). HVIS is very distinctive: it looks like it was sprayed from an aerosol. It is composed of droplets under 1mm in diameter. (A millimeter is about the thickness of a dime.) The issue was, how to make this? Answer: sponges.

Eric did the real shopping, because I was majorly busy, and because he's a superior lab partner. Seriously-- this guy's thorough. He didn't just buy a sponge-- he bought 4 big (4"X8"X2") Ocello sponges, and a pint of fake blood. He bought a sheet of paneling, and some boards. He then reinforced the panel with the furring strips he bought, and transported said paneling, boards, sponges, blood, and some cinder blocks from home to meet me at my private range. Well, it's actually a friend's cow pasture, but for my purposes, it's my private range.

Eric also brought in his SUV a metal rack and some duct tape, along with a lot of brown paper that we had taken from the criminology lab for this purpose. We coated the panel with the brown paper, and I stood it up against the door. Then we took an old rusty range table that's been out there for about 25 years, and stood it about three and a half feet from the wall that we had erected. (HVIS is said to travel not more than four feet.) We wanted to see marginal HVIS. We then suspended the sponge from a board bridging two pairs of stacked cinderblocks, by wrapping one end tightly with duct tape, and hanging the sponge so that it would swing by the duct tape from the board. We took it back down, and saturated the sponge with the fake blood. We put on rubber gloves and poured plenty of the stuff onto the sponge, all the while squeezing it. When it would accept no more "blood," we hung it between the cinderblock stacks, and used an eight-foot piece of wood to measure off our shooting location from the sponge.

I shot the sponge first, using my old S&W M37 Chief's Special Airweight 2", firing a Federal Nyclad 158g hollow point semi-wadcutter +P load into the middle of the sponge.

I was shocked. First: No HVIS. Some bits of sponge had blown out the back and onto the paper, but no HVIS. The heavy bullet load in the minute 2" barrel just doesn't run that hot. Also surprising was that the bullet keyholed. No lie-- take a look. In three and a half feet, the sponge soaked in fake blood took a bullet of serious sectional density and turned it about sideways.

We moved the table closer to the wall, so that the sponge was about as close as it could get without swinging into the wall from the blast-- something over a foot. The bullet again keyholed slightly, but this time we got some HVIS. Not a lot, but some. This is what we were after.

We moved the stack a little more to the left in front of some clean paper, and Eric fired his HK USP compact .40 into the sponge, which we had re-saturated. Using 155g Federal HydroShocks, we didn't expect what happened. First off-- we should have backed the table up to about 4 feet again. What a mess! Take a bullet that weighs 3 grains less but is .043" wider, traveling a good deal faster, with the excellent Hydroshock design, and... well, all hell breaks loose. We had no idea that the Hydroshock would actually expand on the sponge, but it did, and with stability, too! It didn't keyhole at all, passing through the wall with its petals clearly peeled back. The mess was impressive. The back of the sponge was blown out pretty well, too.

We took down our paper, dried it, and folded it carefully, to tape it up and present a practical simulation of a drive-by with two shooters firing three shots total at a person standing in front of a wall.

Then Eric had to shoot the sponge with 00 Buckshot, against the wall, with predictable results.

Predictable, but not enough for Eric. He hung the sponge so that it was edge-on to him, and shot it from about 10 feet, blowing the wad through the paneling this time, as well.

To quote the boys at the Box of Truth: "Shooting stuff is fun."

And we did all this in the name of science.

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At Saturday, May 12, 2007 2:04:00 PM, Blogger HollyB said...

Great blog and great pics. I thoroughly enjoyed this one.
I hope you enjoyed the class as much as I enjoyed this blog!

At Saturday, May 12, 2007 8:53:00 PM, Anonymous Anonymous said...

Matt, you need to look at your ruler a little closer. You stated early on in this post that, "(A millimeter is about the width of a dime.)" I hate to nitpick or split hairs, but a CENTIMETER is about the width of a dime. It takes 10 millimeters to make a cemtimeter.

I agree with hollyb that those photos were great and I think you are on to a good system of teaching.

At Saturday, May 12, 2007 11:19:00 PM, Blogger Matt G said...

Uh, Anonymous? Partner? Try measuring a dime edge-wise.

Seeing as how a dime won't fit down a full-choke 12 ga shotgun muzzle, I would estimate them to be about .68", or roughly (very roughly) 1.5 cm.


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