Forensic ballistics under fire


And in 2016, a government-appointed advisory group of leading scientists and engineers released a study that cited serious concerns about the underlying science of ballistic analysis. The study said the practice relies on circular logic and its “conclusions are subjective.”

“It’s basically a guess,” said Jon Loevy, an attorney representing Pursley’s case in civil court. “I’m sure there’s a lot of ballistics examiners that swear by the science, but that doesn’t make it scientific.”

Specifically, Loevy questioned the subjective nature of the analysis.

“Why do we believe science? It’s not just because it’s a guy who says ‘I’m a scientist’ giving it — it’s because you can replicate results with studies,” Loevy said. “Well, there’s no study that corroborates that this shell casing looks like that shell casing — it’s just some guy’s opinion.”

I know a fair amount about biometrics and it appears some of the same issues which trouble the use of fingerprints are also issues with forensic ballistic analysis. Verification is much better than identification. That is, the examiner can say that the odds that a given bullet (partial fingerprint) matches a given gun (person) with 99% certainty. But given a bullet (partial fingerprint) then finding the correct gun (person) out of the entire population of guns (people) the certainty might be only 0.1%.

Think of it this way: Suppose each gun stamped a number from 1 to 100 on each bullet fired. Given a random bullet and a random gun you could reject 99 guns out of 100 as not shooting the bullet. But if there are 100,000 guns, and the numbers are distributed evenly, 1000 of them could have shot the bullet.

The markings left on the bullets (and shell casings) don’t have sufficient persistent “resolution” to uniquely distinguish between all guns when the population of guns is very large.

Denial of service by a spider

I have a security webcam set up to send me an email of the image when there is movement in its field of view.

A spider decided the camera lens (maybe the IR light was the attraction) was a nice place to do a dance. So… I started getting extremely frequent emails which had large attachments. This filled up the email box on my server and blocked incoming emails from people.

Denial of service by a spider.

It could have been worse. Do you remember my story about denial of service by a dust bunny?

Pro For Sho ear protection

I recently received an email from Michelle of Pro For Sho asking if I would be interested in reviewing their ear protection.

I expressed my interest because of the mention of rifle shooting and their website was up front about their product being useful for shooting.

I frequently put in plugs rather than try to work around the bulky external muffs required to get good protection. And besides, they are claiming 34db NRR when my go-to muffs for pistol shooting when I am alone (Pro Ears) are at best 30db (title says 30db, but the text of the description says 26db) NRR.

I received them today and tried them on. As I expected, they cannot compare to Pro Ears in the softness of the material around the ears (they are amazing!). But they are better than a lot of muffs I have used and I expect they will be comfortable with the one or two hour sessions I have when using passive muffs.

I put on some loud music with plenty of high frequency content and compare the two sets of muffs. I couldn’t determine which were better.

But, my real test was, “Will they allow me to shoot a rifle?”

Here is a picture of my Pro Ears muffs next to the Pro For Sho muffs:


This is a huge difference in clearance between your head and the rifle stock. I got out my rifle in Bellevue (I have another rifle in Idaho I should try it with as well) with the least clearance. As expected the Pro Ears were being pushed up by the stock. The Pro For Sho muffs just barely touched. It’s a win!

Additional information from Michelle:

I just want to mention, since we keep getting a lot of similar feedback from our customers, I think it’s necessary to point out that due to the High NRR Ratio, if you find the earmuffs a bit snug when you first start using them, it’s totally normal. It will loosen up over time. Please FIRST double check to make sure you fully adjust the length of the earmuffs by sliding the cup up and down to find a better fit.

Just in case the earmuffs are still tight, we always suggest to stretch them to make it more comfortable. If the earmuffs are still tight after you fully adjust it, take the earmuffs out and clamp it over the box and let it sit overnight. It worked great with most of our customers who tried it.

MORE INFO ABOUT OUT PRODUCT (just want to save your from checking other resources online 😉

We have two types/sizes of Pro For Sho Shooting Hearing Protection Earmuffs:

1. Pro For Sho 34dB Shooting Ear Protection – Special Designed Ear Muffs Lighter Weight & Maximum Hearing Protection

This comes in one size only, which is Standard Size.

This is a more compact sized earmuffs, which is available in 10 different colors.

2.  Pro For Sho All Terrain Safety Ear Protection

This comes in Large Size and has an NRR of 32dB.

This was also designed with larger ear cups.

This one is specifically built for larger head size, available only in black color.

I would like to point out that the Small size actually is the Standard size which is designed for a universal fit, and the Large size should be Extra Large size. Since Amazon only offers a very limited option of the Size Variation, we had to use Small and Large instead of Standard and Extra Large. We already tried coordinating with Amazon to address this issue.

Ballistic gel tests

I received an email from Brandon B. of Ammunition To Go about a bunch of ballistic gel tests they recently completed. Nearly 100 different handgun loads were tested. See Self Defense Ammunition Ballistic Test for the overview. There are links there to the individual tests but here are the shortcuts to each of the calibers tested:

There were some interesting results in there. I have a probably 400 hundred rounds of some cheap .40 S&W JHP I bought years ago that I thought might use as carry ammo.

And I did use it as carry for a while. But it sort of bothered me that I didn’t have any data to support it being “high quality”. After a year or so I paid about twice as much per round for other ammo that I knew was used by many law enforcement agencies. I have continued that practice ever since. I don’t always buy the same ammo as the previous time, but I always buy something which has been tested and found to work well with the FBI standardized tests. Yes, the FBI tests have some flaws, but if a cartridge performs well in the FBI tests it isn’t likely to be a failure if I ever need “stopping power” in real life.

So, I looked up the cheap ammo in the test results. It did not do well. I might as well use it for practice, reload the brass, and use the shelf space for something else.

The ammo I have more recently purchased did much better.

XKCD for the win

I love the insight XKCD displays at times. This is a great example and so timely:


Whenever you visit XKCD be sure to use your mouse to hover over their image. In this case you will see:

Don’t be nervous about the robots, be nervous about the people with the resources to build them.

Of course, we aren’t too far away from the day when there will be robots to do all the mining, transportation, and processing to build themselves.

Quote of the day—Comfortably Smug‏ @ComfortablySmug

Listen to the sound of their gears and them walking. Remember that sound. You’ll hear it again soon enough as you hide in a closet, holding your child close, fighting the urge to scream. Watching the sliver of light under the door until they arrive.

Comfortably Smug‏ @ComfortablySmug
Tweeted on February 12, 2018
[Skynet smiles.—Joe]

This has to be a coincidence, right?

Via a retweet from David Whitewolf we have this:

6 x 5 x 2 minutes in an hour
8 x 3 hours in a day
7 days in a week

So every month has 8 x 7 x 6 x 5 x [# of weeks] x 3 x 2 x 1 minutes in it.

So there are 8! minutes in February.

Except, of course, on leap year.

This is incredible. This has to be a coincidence. Right?

It would appear so (see also here). In any case, wow!

Quote of the day—Cody Wilson

Gun control is not dead, gun control is undead. We just keep killing it but it keeps coming back.

The handgun is at the center of what is protected in the Heller decision. So, whereas, AR-15’s may not ever be backed up by the Supreme Court, there’s no way of getting around, right now, the protections that the Supreme Court gave to the handgun. And so this is the core of the Second Amendment liberty as it’s currently understood.

Cody Wilson
Director of Defense Distributed
February 5, 2018
Want to Make an Untraceable Handgun at Home? Cody Wilson Can Help.
[For certain values of “understood”.

These are interesting times we live in.—Joe]

Cell phones are good for rats

Back in the early 2000s I talked to a researcher who said he did tests which showed that rats exposed to satellite phone radio emissions had fewer cancers than rats not exposed to the radio emissions. Then about two years ago more research indicated the same thing with conventional cell phones.

Today, another study came out which reported:

The radiated rats somehow lived longer than comparison rats that were not exposed to cellphone radiation.

Okay, I’m convinced. If you want your rat to have a long and healthy life you should give it a cell phone.

D-DAY Through German Eyes

My brother Doug told me he recently read D DAY Through German Eyes and really enjoyed it. I am almost finished with the second book now. It’s very good. There were a number of things I learned about the weapons the allies had but what I have enjoyed most was what the German soldiers believed they were fighting for.

I didn’t realize the allies had planes and ships that fired rockets. I thought the planes only had guns and bombs. And I thought the only weapons the ships could use against land based targets were their guns and planes from the aircraft carriers.

Some of the rockets had phosphorous warheads. There were also warheads with explosives and ball bearings which were used for anti-personal as well as anti-material. And amphibious tanks! This surprised the Germans too. Some of the tanks also had flame throwers. The Germans really didn’t like the flame throwers. Some refused to go back into battle facing the phosphorous and flamethrowers even though the alternative was an expedited court marshal and execution the same day.

There were Russians who defected on the Eastern Front and joined the Germany army who assigned them to the western front. When the allies took prisoners the Russians were separated from Germans and handed directly over to the Russians. The Russians executed them. There were thousands of them.

One soldier told of the “Browning Assassination Pistol”. From the description it has to be the FP-45 Liberator. What I found most interesting is that the soldier (a military policeman) who mentioned them said thousands of them were distributed in France and probably hundreds of German soldiers were killed by French civilians with them. This is in direct contrast to what Wikipedia says about them.

The MP was guarding a small group of Germany officers the night before D-Day. As the bombing started they went to a private residence set up as a small hotel for the officers. After dinner one of the waitress suggested to one of the officers that he looked tired and perhaps he would like to go to bed (it was implied the waitress went to bed with him). He did. Later the other officers wanted to speak with the “sleeping” officer and the MP went looking for him. He found him in the bedroom, a hole in his head, blood all over, and a “Browning Assassination Pistol” on the floor. All the hotel staff were gone.

Did you know that Germany was actually protecting France? They needed to be protected from the International Socialists to the East, so there was a partnership between the French and Germany governments. The Germans were National Socialists but that wasn’t a threat to the people of western Europe. Germany united Europe. This was good for people of Europe. Why would the Americans and Canadians have a problem with that? Sure, the British hated the French and wanted a piece of France, but the Germany was protecting France from the British and the secret societies (the Free Masons) to the west who were being manipulated by the international bankers.

At least that is what was believed by many of the German soldiers.

High altitude highway

Via Boomershooter “Squirrel Hunter” we have the Karakoram Highway

The Karakoram Highway (KKH) is one of the highest paved international roads in the world. It connects the Xinjiang Uyghur Autonomous Region of China and Gilgit–Baltistan of Pakistan across the Karakoram mountain range, through the Khunjerab Pass, located at 36°51′00″N 75°25′40″E, at an elevation of 4,693 metres (15,397 ft).

Connecting China’s Xinjiang region with Gilgit–Baltistan region of Pakistan, the road is a popular tourist attraction. Due to its high elevation and the difficult conditions in which it was constructed, it is referred to as the Eighth Wonder of the World.

Wow! And I thought Idaho, Washington, Montana, and Colorado had some “interesting” switchbacks and high altitude construction on some of their mountain roads.

Nope. Nothing I have seen in the states even begins to compare.

That’s what I carry

This is kinda cool. FBI Selects Winchester’s .40 S&W Ammunition for Duty and Training:

The Federal Bureau of Investigation (FBI) has completed an extensive evaluation process and Winchester has been chosen as its primary source for .40 S&W pistol ammunition. This includes a bonded jacketed hollow point (JHP) service cartridge as well as full metal jacket (FMJ) and frangible training loads. Winchester has been supplying the FBI with service and training ammunition for many years and is honored to be awarded the most recent contract and continue to support our nation’s premier law enforcement agency.

The 180 gr. bonded jacketed hollow point (JHP) cartridge selected by the FBI is designed with patented technology that utilizes a reverse-jacketed, bonded bullet that can penetrate a wide variety of intermediate barriers while maintaining very consistent target penetration and reliable expansion. The nickel-plated cartridge prevents corrosion and ensures smooth feeding and extraction. Flash suppressed powder is used in this cartridge to maintain an agent’s night vision and meet the FBI’s stringent darkened range evaluation.

The Winchester .40 S&W, 180 grain, JHP cartridge (Ranger) is my carry ammo.

Update: In the comments John Hardin asked if the FBI chose the Ranger bullets. I think the answer is yes. As near as I can tell the “reverse-jacketed” bullet refers to their patented reverse taper (thick near the opening, thinner on the sides and base) JHP with with the jacket pre-scored in the area intended to expand. This gives the uniform size and characteristic hooks at the end of the “petals”:


Winchester sells several different 40 S&W 180 grain JHP cartridges. Two of them appear to use the same bullet, the W40SWD and S40SWPDB1 cartridges. A third, USA40JHP, appears to be using a conventionally jacketed bullet:


There are also what appear to be different brandings, and/or nickel plated brass casings, of these same three cartridges:

So, I believe the FBI must have chosen a cartridge with the same bullet as what is in the Ranger bonded cartridge.


I already know C#, I guess it’s time to learn Q#:

Microsoft today launched a preview version of a new programming language for quantum computing called Q#. The industry giant also launched a quantum simulator that developers can use to test and debug their quantum algorithms.

The language and simulator were announced in September. The then-unnamed language was intended to bring traditional programming concepts—functions, variables, and branches, along with a syntax-highlighted development environment complete with quantum debugger—to quantum computing, a field that has hitherto built algorithms from wiring up logic gates. Microsoft’s hope is that this selection of tools, along with the training material and documentation, will open up quantum computing to more than just physicists.

We are living in the future.

I’m not sure how to interpret the feelings this causes in me. I think it might be fear.

Quote of the day—John D. Clark

The old destroyer gun turret which housed our card-gap* setup had become a bit frayed and tattered from the shrapnel it had contained. (The plating on a destroyer is usually thick enough to keep out the water and the smaller fish.) So we had installed an inner layer of armor plate, standing off about an inch and a half from the original plating. And, as the setup hadn’t been used for several months, a large colony of bats —yes, bats, little Dracula types —had moved to the gap to spend the winter And when the first shot went off, they all came boiling out with their sonar gear fouled up, shaking their heads and pounding their ears. They chose one rocket mechanic —as it happens, a remarkably goosy character anyway—and decided that it was all his fault. And if you, gentle reader, have never seen a nervous rocket mechanic, complete with monkey suit, being buzzed by nine thousand demented bats and trying to beat them off with a shovel, there is something missing from your experience.

John D. Clark
I G N I T I O N !: An Informal History of Liquid Rocket Propellants, page 171
[I love this book.—Joe]

* The card-gap test is used to determine the shock sensitivity of a potentially explosive liquid. A 50-gram block of tetryl (high explosive) is detonated beneath a 40 cc sample of the liquid in question, contained in a 3″ length of 1″ iron pipe sealed at the bottom with a thin sheet of Teflon. If the liquid detonates, it punches a hole in the target plate, of 3/8″ boiler plate, sitting on top of it. The sensitivity of the liquid is measured by the number of “cards,” discs of 0.01″ thick cellulose acetate, which must be stacked between the tetryl and the sample to keep the latter from going off. Zero cards means relatively insensitive, a hundred cards means that you’d better forget the whole business. As may be imagined, the test is somewhat noisy, and best done some distance from human habitation, or, at least, from humans who can make their complaints stick.

Quote of the day—Bruce Schneier

The market can’t fix this. Markets work because buyers choose between sellers, and sellers compete for buyers. In case you didn’t notice, you’re not Equifax’s customer. You’re its product.

Bruce Schneier
September 13, 2017
On the Equifax Data Breach
[I agree with his astute observation but not his conclusion (government legislation is required).

If someone is harmed by the carelessness of another the careless person can, and rightly so, be sued for damages. How is this any different?—Joe]


It’s Gravity season. Time for things to fall. Things like leaves and branches. On power lines, naturally. And roads. Oh joy, be still my beating heart! Since Hurricanes Harvey and Irma and Maria, I’d been meaning to dig out the generator for a test run, and do my other fall emergency checks. Thus begins a short story of preparedness and failure. Continue reading

Dystopia idea became a blueprint

I hate it when governments take some dystopian concept and use it as a blueprint rather than a warning:

It is a CCTV clip showing current surveillance in China. Thanks to artificial intelligence (AI), facial recognition technology, GPS tracking and 20 million CCTV cameras, China’s sadly named “Sky Net” system demonstrates just how creepy real-time surveillance can be.

According to a documentary that ran on China Central Television, the security cameras use facial recognition to identify each person and then overlay a popup of personal information on the screen by the person. Descriptions include details such as age, gender, and other features such as clothing color. This happens in real time.

If you saw the TV series Person of Interest, this is the implementation of it under the control of the Chinese government. The show was pretty good. But a tool like that in the hands of any government is really bad news.

Current Chinese Surveillance System are something out a sci-fi film

H/T Josh J. via email.

Quote of the day—Ray Kurzweil

We have already eliminated all jobs several times in human history. How many jobs circa 1900 exist today? If I were a prescient futurist in 1900, I would say, “Okay, 38% of you work on farms; 25% of you work in factories. That’s two-thirds of the population. I predict that by the year 2015, that will be 2% on farms and 9% in factories.” And everybody would go, “Oh, my God, we’re going to be out of work.” I would say, “Well, don’t worry, for every job we eliminate, we’re going to create more jobs at the top of the skill ladder.” And people would say, “What new jobs?” And I’d say, “Well, I don’t know. We haven’t invented them yet.”

That continues to be the case, and it creates a difficult political issue because you can look at people driving cars and trucks, and you can be pretty confident those jobs will go away. And you can’t describe the new jobs, because they’re in industries and concepts that don’t exist yet.

Ray Kurzweil
September 24, 2017
Why Futurist Ray Kurzweil Isn’t Worried About Technology Stealing Your Job
[That has been my hunch too, but I can’t supply evidence to refute the claim, “But this time it’s different!”—Joe]

This could save millions

This is great news:

Scientists have engineered an antibody that attacks 99% of HIV strains and can prevent infection in primates.

It is built to attack three critical parts of the virus – making it harder for HIV to resist its effects.

The work is a collaboration between the US National Institutes of Health and the pharmaceutical company Sanofi.

The International Aids Society said it was an “exciting breakthrough”. Human trials will start in 2018 to see if it can prevent or treat infection.

If this works out the people of Africa will probably benefit the most, but there is no continent that won’t have significant number of lives saved if there is near universal vaccination of those at risk. And if the technology can be adapted to other viruses, even just colds and flu, it will be a significant win for humanity.