Homemade Rifle Barrels Using Electro-Chemical Machining



This is a followup on yesterday’s post. While I surely have the technical ability to pull this off, I just don’t have the time. I’m curious to hear from any readers who have experimented with this.

Precision Rifle Matches

I’ve been shooting local precision rifle matches to hone my craft. I completed the second match two weekends ago. If you are near Navasota, Texas, check out TX Precision Matches. They hold matches the second Saturday every month. Shooters need $50 and 100 rounds.

The shooting is challenging, and humbling. The target size is 1-4 MOA, with 2.5 MOA or so being the average. The match features 8 stages. Each stage is 105 seconds, and 8-12 rounds fired. The match typically runs from 0830-1500. The target range is from 350 yards to 1100 yards, with a typical target being at 500 yards. Most shots are from non-prone positions.

TX Precision indexes shooters’ scores off of the leader in your division. The leader gets a 100%, and other shooters get percentages of the leaders score. If the top score in a given division was 60, and a shooter scored a 45, then his score is 75%.

I can’t recommend enough that you go to these local matches to skill build. The shooters are incredibly helpful, and will shepherd first timers through the whole match. Come prepared to be humbled. You probably won’t score well your first few outings. No, it doesn’t mean you suck. It also doesn’t mean that the sport is stupid. It’s a great chance to learn alternate positions, rapid wind calling, and applying the fundamentals under severe time stress.

The divisions are Marksman, Expert, and Pro for bolt guns. Gas guns are a separate division. A look at the scores shows why. I’ve always known from personal experience that bolt guns are more accurate than gas guns, but the low gas gun scores surprised me.

Mountain Guerrilla: Drill-Building for Skill-Building

Balance in training is key. You should drill fundamentals and incorporate more realistic and force-on-force work. Be wary of trainers that suggest ditching square ranges. Likewise, understand the square range is crawl/walk; you need further drills for the run phase.

MG Article

INTRO:

It’s become something of a cliché, in the training world, to point out that “Life isn’t a square range!” The implication—and sometimes it’s not even implied, but violently explicit—being that if you’re doing fundamentals work with your weapons, you’re going to die, because your training isn’t “real” enough. I’ve always found this ironic, since in my experience, the ability to actually hit what the fuck I was shooting at, on demand, as many times as I needed to shoot it, was THE defining factor in success in a gunfight. Where did I learn to do that? On the fucking “square range!” Admittedly, they were actually, usually rectangular, but…

Windage Field Constants for Common Rifle Calibers

For the benefit of the rifle shooting community, I have created this table of common calibers’ wind constants. If you’d like to see another bullet on this table, just post the request in the comment section, and I will update the table (weight, G7 BC, and MV would be helpful). I have gotten it kicked off with 6 common calibers. I made this table using my highly accurate ballistics calculator, Sendit Ballistics. The table is right below. Further explanation is below the table.

You better have some way of getting on paper in this atmospheric shit-storm.

Corrections Table

CaliberRanges Valid To (m)Wind Constant (mil, meter, mph)Wind Constant (moa, yard, mph)
5.56mm, M193, 55gr FMJ, 600206.4
5.56mm, M262, 77 gr BTHP, 2740fps MV800278.6
5.56mm, M855, 62grn FMJ600237.3
6.5mm (CM), 140grn ELD-M10004514.3
7.62mm (300WM), Mk248Mod0, 190gr BTHP11004414
7.62mm, M118LR, 175gr BTHP, 2600fps MV8004012.7
.22 LR, 40gr CCI Mini-mag, rifle40082.5

Having a windage field constant in your back pocket is a great thing for serious shooters. A field constant means a single number which helps you come up with corrections based on a full value wind, and the given range.

The concept of a wind constant works on the following equation:

Meter Line * Windspeed / Constant = Correction

EXAMPLE: 5.56 62grn at 400 meters (meter line 4),
in a 6mph wind. Want MOA correction.

1. Constant = 7
2. Correction = 4 * 6 / 7 = 24/7 = 3.5MOA
  • Meter Line is in hundreds, i.e. the Meter Line for 500m is “5”
  • Windspeed is full value, interpolate for half values
  • Constant is in such a unit that it gives you the desired correction

I made the table with two types of constants. The first row is for shooters who desire a mil correction, with meter distances, and mile per hour winds. The second column shows MOA corrections, for shooters shooting in yards, and using mile per hour winds.

You will notice that some of these constants are non-rounded numbers. I decided to err on the side of giving the rifleman the most information. If you don’t like “27,” you can make the call to round it to “25.”

Methodology

The wind constant calculations are pretty much pure analytical science. I used the ballistics engine in Sendit Ballistics to produce the corrections for the given bullet and wind parameters. From there, it is simple algebra to calculate the wind constant (see the simple equation at the top of the page, we need to know 3 numbers to find the 4th). I modeled the wind constant at every hundred meters, and at 5, 10, and 20mph for each cartridge.

Past those calculations, there is some art involved. I first average all the wind constants to get a baseline number. This number is typically too low. The wind constants change drastically from 100m to 1000m. The constants are higher at shorter ranges, meaning that ultimately they produce smaller corrections for the riflemen in the field. Of course, the small wind constants at long range produce corrections which are too big at medium ranges. The key is to pick a reasonable range for the given cartridge, and then select a wind constant that will give adequate coverage for both medium and long ranges for that cartridge. It’s not too much of a problem if the shooter overcorrects by a large amount at shorter ranges; it amounts to centimeters.

Sendit Ballistics

Check out Sendit Ballistics for iOS if you are interested in an accurate, simple bullet trajectory calculator. I keep an updated page on the app here. The app is so accurate because it models the most important 3 degrees of freedom with painstaking detail. The app is designed for the field user, with a simple interface, range card mode, low light mode, and rapid corrections with minimal information. It is free to 400 meters, and only $4.99 to infinity.

Book Review: Victoria, William Lind

4.7 / 5.0

Bottom Line: Victoria is a teaching tool for 4th Generation War (4GW) students. This book is a very good series of short stories which help readers build an intuition for 21st century and beyond war, which will be 4GW to a large extent.

Review

This book should not be viewed as a novel, although that is how it is presented. It is really a series of short stories, loosely tied together on the theme of a future collapse in the liberal global order. Though the political setting of the book is designed to make Lind’s dedicated fans feel at home, it’s not really important for a serious 4GW student. I’m just as happy studying Hezbollah as I am a movement of traditionalists in the United States, which is the best way to describe the protagonists in Victoria.

The basic pattern of Victoria is to present a seemingly difficult problem, which the protagonists then solve by using a mixed and innovative approach, characteristic of successful 4GW. Lind’s intent seems to be to use each chapter to present a realistic pattern for a future conflict, and to then show how a thinking man would solve it.

In one instance, they defeat local politicians by recruiting friendly media outlets to create a public firestorm. In another, they use WW2 era tanks to make rapid 3GW maneuvers once the danger of air attack as passed. In still another instance, they recruit criminal organizations to set off a bomb near an enemy port, which gives the appearance they have more power than they really do.

Though the book has a loose storyline, it isn’t necessary to read it in order. The book has some value as a reference; the reader can flip back to a chapter that relates to current events or a historical scenario in order to get insight into the power dynamics between the two sides.

Lind’s military background included his part in a very serious attempt to reform the US military in the late 1980s to be a 3rd Generation War force. 3GW is the German Blitzkrieg, Nathan Bedford Forrest, and the US Army in Desert Storm. The point is to break through an enemies lines with speed, and disrupt them at the operational level. According to Lind, the US military generally practices 2GW, which means to bombard the enemy with pre-assault fires, and then assault to take ground.

This background probably explains why Lind seems to strongly eschew 2GW in this book — he figures we have enough examples of it in current events and history and it does not need to be taught. By contrast, the book features a good bit of 4GW, some 3GW, and even a particular scene of 1GW. Part of 4GW also means to use and time the other generations of war to maximum information and strategic effect.

More on Victoria’s Learning Model

I am curious as to whether William Lind intentionally used the experiential learning model (ELM). The ELM is a learning model intended to touch on the primary ways adults learn, and Victoria seems to follow this model to engage as many adult readers as possible.

The Concrete Experience is simply reading an engaging scenario. Observation and reflection is really discussion, and it occurs in Victoria through the dialogue. Abstract Concepts means lecture style learning, and occasionally occurs as during soliloquies by Rumford or Kraft, the two main protagonists. Testing in new Situations is really a practical exercise, and of course cannot occur in a book.

The Bad and Ugly

There isn’t much bad about the book. Parts of it are kind of corny. The storyline is somewhat loose. The depiction of The South is downright cartoonish and grating. I give Lind a pass on this in general, because his portraying nations in stark contrasts allows him to better illustrate subtle 4GW cultural concepts.

Ultimately, this book is a good set of stories that illustrate various realistic 4GW situations. Even the unintelligent will get an entertaining novel out of the deal. Intelligent 4GW students will use this book to build their intuition about 4GW situations, as well as get guidance from the protagonists’ reading lists for further study.

Sendit Ballistics 1.3.0 Released (Thanks Beta Testers)

1.3.0 is an incremental upgrade which makes the operation of Sendit Ballistics smoother. The long and short of it is that I am removing the “default units” switch, which makes a user choose between either metric or standard.

It was a dumb system that made sense in my engineer mind at the time. Unfortunately, it’s just not how real shooters work, as I should know. I use meters and mils, mph for wind, F for temperature, and mbar for pressure. In other words, a mix. Beta tester “E” helped me to see the error of my ways, and for that I’m grateful.

Well, what are you waiting for? Download the improved app!

Terminal Ballistics from The Weapon Blog

Weapon Blog has posted some excellent articles lately on terminal ballistics. Really, they are videos of people shooting things. Is there any other way to conduct terminal ballistics modeling? In terminal ballistics, empirical data rules over analytical solutions.

In the first video, the shooter fires multiple calibers at a pine tree to determine which ones will penetrate.

In the second video, the shooter fires 5.56, 9mm, and 22LR through multiple layers of drywall.


AR-15 Wind Corrections Made Easy

The AR-15 series is a Rifleman’s rifle. It is accurate, customizable, and easily maintained. Even with off-the-shelf Full Metal Jacket (FMJ) ammunition, it’s a 3-MOA gun. In other words, a 5.56mm can hit a man-sized target at 600 meters without any customization or match ammunition. As many users have verified, upgraded stocks, optics, and ammunition can extend this range. This accuracy holds during good weather.

During wind, the burden of accuracy shifts from the AR-15 (accurate 3MOA or better), to the shooter or spotter who is calling the wind. Out to 100 meters, the wind would need to blow at roughly 60mph to move a bullet off of a man-sized target. Even at 300 meters, the shooter can get away with holding on the left edge or the right edge to compensate for any wind under 15mph.

At 400 meters and further, incorrect wind calls will lead to misses. A mere left or right edge hold limits the shooter to a 7.5mph wind. In other words, the AR-15 shooter’s lack of wind calling skill limits the platform’s effective range to 400 meters on a significant number of days.

The Rule of 7 for 5.56

The Rule of 7 for 5.56 is simple. To get your windage hold, multiply the meter-line and the windspeed in mph, and divide by constant 7.

Example 1:

500 meters, 4mph wind, full value. Need MOA correction.

MOA = 5 * 4 / 7 = 2.85.  Round to 2.75 or 3.0 MOA

Now, you need to know the value of the wind. Your gun is pointed at the 12 o’clock. 12 and 6 are no value. 3 and 9 are 100% value. 11, 1, 5, 7 are 50% value. 2, 4, 8, 10 are 70% value.

Example 2:

620 meters, 8mph wind out of the 1’oclock. Need MOA correction.

MOA = 6 * 8 * 0.5 / 7 = 3.43. Round to 3.5 MOA

Perhaps you don’t have a scope or reticle that works in MOA. You want inches so that you can hold off of the target into space. Remember, shoulder-to-shoulder is 19″ on an average male. Simply multiple the MOA correction with the meter-line.

Example 3:

400 meters, 16mph wind out of the 4’oclock. Need inches.

MOA = 4 * 16 * 0.7 / 7 = 6.4. Round to 6.5

Inches = 6.5 * 4 = 26 inches of hold.

Accuracy Check with Sendit Ballistics

We’ll use Sendit Ballistics, my iOS app, to check the accuracy of the rule, assuming 62-grain 5.56 at 2970fps. Wind is full value 10mph.

200 meters: 3 MOA by Rule of 7, 2 MOA by Sendit Ballistics

400 meters: 6 MOA by Rule of 7, 4.5 MOA by Sendit Ballistics

600 meters: 8.5 MOA by Rule of 7, 8.0 MOA by Sendit Ballistics

800 meters: 11 MOA by Rule of 7, 12.0 MOA by Sendit Ballistics

 

In other words, keep the Rule of 7 in your back pocket for windy days! And keep Sendit Ballistics in your back pocket too, in case you need perfection.