Swatting was taboo

Friday, April 12th, 2019

On his way back to the States from Egypt, Dunlap passed through Nigeria:

Also, that part of the world has more bugs and insect life in general than any other place on the planet. We slept under mosquito bars for the first time and I thought the net would break under the weight of the inquisitive night visitors who landed on it; one type of critter was very numerous and could only be shooed away, as it had a very obnoxious odor when liquidated. Swatting was taboo. Except for our using Arabic words by force of habit we got along OK with the native help along the way. They did not understand it and we were so used to Egypt that we used some common words by reflex action on all the dark-skinned waiters and porters we saw.

The typical range estimation error for trained soldiers is around 30%

Thursday, April 11th, 2019

The French military experimented with a high-tech grenade-launcher for the same reasons the US did:

In the 1950s, the answer to the low hit probability of the average soldier at ranges higher than 100 m was the ”controlled dispersion” concept of full-auto fire, leading to the reduced-recoil 5.56 mm round.

The difficulty in implementing this concept (the recoil of the 5.56 mm round was still high enough to induce too much dispersion in a lightweight rifle), led to a shift from a burst of multiple kinetic energy projectiles to the use of a single high-explosive, fragmenting round, the fragmentation pattern taking care (at least on paper) of aiming errors.

The PAPOP project (Polyarme-Polyprojectile, similar to the US OICW) launched in June 1994 was intended to combine grenade launcher (for long range engagements) and a “kinetic energy” system for engaging targets at shorter range.

[...]

The project did not go very far, as the weight of the combined weapon was found to be too high and the grenade carrying capacity too low.

The effective casualty radius of air-bursting grenades was also found to be very small (between 14 m² against unprotected standing target and only 4 m² against protected prone target in the most favourable case of the 35 mm grenade), and very sensitive to bursting height & grenade falling angle. All in all, it was found that in order to be effective, the detonation of air-bursting grenades needed to be triggered with an accuracy of ~1 m in both range and direction, and 0.5 m in height, an unreasonable expectation for a hand-held weapon on the battlefield.

It should be pointed out that due to their low velocity, grenades are a very different beast than bullets and that without the help of a laser rangefinder, aiming errors with a grenade launcher are a full two orders of magnitude higher than for a rifle, nearly negating all of the benefit of the large casualty radius produced by the grenade fragmentation warhead at long range.

According to US results, the typical range estimation error for trained soldiers is around 30%, so for a target at a “true” distance of 288 m (for example), even a trained soldier will hesitate between the 250, 275, 300 and 325 m setting on his grenade-launcher sight (an average miss distance of 25 m before even taking into account the intrinsic weapon dispersion, compared with a typical grenade effective radius of 5 m to 10 m), and will need to “walk his fire” to the target at range longer than 150 m, a very difficult task with single-shot grenade launchers.

Even with a tripod-mounted laser rangefinder, operated by a trained spotter in a prone position, the average range error measurement is around 5% of the distance, and could be as high as 9.3%. At 600 m range, that’s an average error of 30 m, much more than the expected casualty radius of this class of warhead.

Typical defensive hand grenades that use a very simple (compact and lightweight) fuse weigh in between 400 g and 500 g, and have a reported casualty radius of around 10 m, so it is doubtful that a 20 mm to 40 mm spin-stabilized grenade with a weight between 100 g and 200 g could achieve a much better casualty radius.

If the same range measurement error could be achieved with a hand held (or shoulder held) device, combined with a 5 m to 10 m effective radius grenade, then a 300 m practical range could be claimed, but a 600 m practical range will require the measurement error to be halved.

Ruin any herrenvolk for about a 30-yard radius

Thursday, April 11th, 2019

While in Egypt, Dunlap saw a demonstration of the then-new British bakelite grenades — two of which looked alike, but acted differently:

One was just a blast type, which could be thrown and disregarded if over a few yards away, and the other a vicious fragmentation type which could ruin any herrenvolk for about a 30-yard radius. They looked alike, so if an enemy saw one coming he had to take cover, while the thrower knew what he had and could throw a blast type and run up on the enemy position while the Kraut had his head down.

I’m surprised more gear isn’t designed with this in mind. “All warfare is based on deception.”

Only bullets that hit count

Wednesday, April 10th, 2019

The Hitchman report paved the way, Emeric Daniau argues, for numerous studies that tried to evaluate the rifleman’s effectiveness under what was considered “realistic” stress conditions and tried to provide a technical answer to the perceived lack of effectiveness at ranges longer than a hundred meters:

The founding idea of those studies (like ORO-T-160, but also SALVO I & II, SAWS and several others) was that “only bullets that hit count”, and that the only military effect of small-arms fire (and Individual Weapon fire in particular) was hitting and disabling a target. Suppression effects that are known to greatly reduce enemy fire effectiveness and enemy movements (two very interesting military effects) were simply not taken into account and no effort was made to try to evaluate them, or incorporate results of other studies devoted to such topics.

This idea of limiting the effectiveness of small-arms fire to hitting and disabling enemy soldiers immediately calls upon past visions of glorious battlefields where dense masses of soldiers were shooting at each other, or where a handful of brave souls stand against a “human wave” assault of mechanized infantry (“high density” battlefields), but seems totally remote from the “low density battlefields” so frequently encountered during “decolonization” wars or peacekeeping / stabilization engagements.

From a methodology point of view, this choice (deliberate or not) to reduce military effectiveness of Individual Weapon fire to “bullets that hit” had major implications. First, the complexity of evaluating small arms effectiveness was greatly reduced, “scientific” evaluations could be performed and focused on hit probability (pH) and terminal effectiveness (pI/H) against unprotected targets, or after defeating personal protection (but not intermediate barriers).

Second, since the maximum effective range considered (300 m) is relatively short, almost any bullet pushed fast enough could do the assigned job (hitting and delivering “sufficient” terminal effectiveness).

Of course, the capability to hit something is very valuable, but what is the hit probability of a soldier in a real combat, as opposed to simulated combat?

The “shots to casualty” ratio of small-arms fire is a highly debatable issue, and numbers as high as 100,000 have been quoted, but without a strong database to sustain that claim.

More reliable values could be found in the experience of the First Australian Task Force (1ATF) during the Vietnam war, with (mean) values of 187 shots per casualty for the 7.62 mm SLR and 232 shots per casualty for the M16 in the context of day patrol.

Nearly 80% of those engagements took place at ranges shorter than 30 m, not really long range, and still the average hit probability was around 0.5%, compared to a hit probability of ~100% found in ORO-T-160.

Of course, “mean” values are only average and in particular events close to “ideal” shooting scenario, shots-to-casualty ratio around 30 to 1 were achieved. While this number (pH ~3%) is definitively higher than 0.4% or 0.5% (nearly one order of magnitude), it’s still a very substantial difference from results commonly found during simulated combat.

The French operation in Mogadiscio in June 1992 could be seen as a very good example of effective firing, but even in this scenario ~3500 small arms (5.56 mm and 7.62 mm) rounds and ~500 12.7 mm rounds were expanded to produce a maximum of 50 casualties (pH of 1.25 %).

Police shootings that take place at very short range (generally less than 7 feet) exhibit the same symptoms of very low hit probability, one or two orders of magnitude less than expected. For example, during the famous 1997 North Hollywood shootout, the two heavily armed bank robbers fired approximately 1100 rounds during a 44 minutes battle and wounded 11 police officers (pH ~1%) and 7 (probably untargeted) civilians.

In return, police officers fired an estimated 650 rounds and killed both perpetrators (it is possible that one committed suicide after being wounded). Both bank robbers wore homemade bulletproof garments and one was hit several times in rapid succession in his legs until he surrendered (he died later from blood loss), so it’s difficult to evaluate the hit probability of the law officers, but even at a few feet, with good visibility and superior training (the final part of the shootout was conducted by SWAT members at a distance around 3-4 meters), one should expect results probably not much higher than 5% to 10%, again a substantial difference between “real life” results and results recorded during simulated combat.

This difference could be easily explained because of course, during simulated combat, no matter the amount of “realism” of the shooting scenario (sounds, fumes, explosions, fatigue or even electric shocks on the shooters), the targets are not returning fire so soldiers could focus on “clearing the range” (and freely expose themselves during the process), while during real combat trying to minimize exposure time to avoid being hit is mandatory.

So, if we look back at Figure 30, we have an idea of the hit probability of a soldier firing his M1 rifle at a human-size target with an exposure time of 3 seconds.

In order to be able to hit this target, the soldier needs also to expose himself to incoming fire (from his target, or from other people waiting for a shot of opportunity, the battlefield is not a place for a duel) during roughly the same amount of time.

[...]

Evaluating the dispersion of hand-held weapons and trying to improve the hit probability was at the heart of both ORO-T-160 and ORO-T-397 (Salvo II study).

Most results found in ORO-T-160 used a target exposure time of 3 seconds and shooters were discriminated between “experts” (highest skill) and “marksmen” (lowest skill).

During those tests, “experts” scored significantly higher than “marksmen” (another “argument” against long-range firing in the hands of the masses). For example, during the second test, “experts” scored 8 hits (25% hit probability) on a man-size target at 310 yards (Figure 33), when “marksmen” scored only 2 hits (6% hit probability, Figure 34).

During those test, a large cloth was used to record as many shots as possible (hits and near-misses), and it’s interesting to notice that in both cases:

  • the number of shots recorded was nearly the same (25 for “experts” and 26 for “marksmen”),
  • the dispersion of shots was nearly the same (~7.25 mils for “experts” and ~7.5 mils for “marksmen”),
  • the number of rounds impacting in a 1 m circle around the head of the target was the same (23 shots, or 72%, in both cases), the only significant difference is the mean point of all impacts, “on target” for “experts” and slightly off target by 35 cm for “marksmen”, this shift of MPOI alone explains the difference between a hit probability of 25% and 6%. A deviation of 35 cm (~14 inches) at 310 yards is what you can expect from a 15 mph lateral wind acting on the .30-06 M2 bullet,
  • a third test was performed, using a 1 second target exposure time and a random schedule between two targets, one located at 110 yards, and one located at 265 yards (table A3 in ORO-T-160, p.100), and under those firing conditions the “marksmen” greatly outperformed the “experts”. Unfortunately, results obtained during this third test were not reviewed as deeply as results obtained during test n°1 and n°2, and no conclusion was drawn from it.

That last point makes it clear that we weren’t training riflemen to shoot quickly.

During the SALVO II study (ORO-T-397), a similar test was performed. The dispersion of each individual soldier was measured (“Experts”, mean dispersion between 1.97 mils and 2.93 mils; “Sharpshooters”, mean dispersion between 2.12 mils and 3.67 mils; “Marksmen”, mean dispersion between 2.30 mils and 3.70 mils) and from the conclusions of this report, it is clear that the level of marksmanship (for a given training program) plays only a small role in hand-held weapons dispersion compared to target exposure time and visibility (Figure 35).

The 7.5 mils and 7.25 mils obtained for “marksmen” and “experts” respectively, for a target exposure time of 3 seconds found in ORO-T-160 (published in 1952) are close to the “upper bound” found in ORO-T-397 (published in 1961) and probably reflect the change of marksmanship training (TRAINFIRE I was introduced in 1954, and TRAINFIRE II in 1957), from “bull’s-eyes” targets to “popup” targets.

Mean dispersion found in ORO-T-397 was around 3 mils for a target exposure time higher than 5 seconds, and this dispersion was increasing as the exposure time was decreasing, up to 7–7.5 mils (24 MoA to 26 MoA).

[...]

So, there is a wide difference between the way we evaluate small-arms hit probability and “real-life” results which seem to range from 0.3% to 3%, even at fairly close distances. From an individual fire perspective (one soldier, one target and one bullet), this value could be considered low, but from a tactical point of view, with tens to hundreds of soldiers, each carrying more than a hundred rounds, it’s high enough to produce decisive military results.

For example:

  • during the battle of Magersfontain in December 1899, fire from the 8,500 Boers’ individual weapons (Mauser bolt action rifles) at a range of around 400 yards (366 m) was sufficient to kill and wound 665 British soldiers (24.5% of the total) in the first 10 minutes of the battle,
  • a few days later, during the battle of Colenso, 2 British batteries (12 guns) of field artillery were engaged by rifle fire at a distance of 700 m. Suffering heavy casualties, the British were forced to fall back to their camp, losing 10 guns in the process.

[...]

The adoption by the US, followed by NATO, of the .223 Remington cartridge as the 5.56 x 45 mm, was not the result of concluding that the battlefield depth (measured in kilometres before WWI) was now reduced to 300 m, but an acknowledgement that effective HE support could be provided now at very short range in most conditions, and that the fire delivered by the infantry individual weapon should be used only for defeating adversaries in the 0 to 300 m bracket, longer ranges being devoted to collective weapons firing heavier ammunition.

These could sit up like a woodchuck and run a lot faster

Wednesday, April 10th, 2019

Dunlap had some experience with the local fauna in Egypt:

The Lieutenant and I usually had Lugers stuck in our back pockets, and always went armed after we ran into a pair of horned vipers at the butts. The day that happened I sent the medic in to the hospital for a snake-bite kit and instructions, etc. (we always had an ambulance and a couple of Medical Corps men in it, as part of the range equipment, just in case). He came back and said nobody knew nothin’. However, our report of the vipers stirred up some action and we did get quite a lot of dope on snakes in a day or two, as well as medicine, etc. These vipers are a short heavy snake, with horns and extremely potent venom. They can move under loose sand, and one of the first two I saw popped its head up out of the desert, like a turtle’s head in the water when he’s trying to get a good look around. No one ever got bitten, but I don’t know why, for there were plenty of the snakes around. It turned out that Egypt has quite a few dangerous reptiles, though I am still amused over finding out about Cleopatra’s asp. You know the cute little critter she is always holding in the pictures? Forget it; the Egyptian asp is a six-foot water-snake, living around canals and rivers. The viper is the bad little one. Snakes and lizards were the only wild life out by our range and we polished off quite a few via Luger and Springfield. The lizards were very repulsive, but harmless characters looking more like a long-legged miniature alligator rather than the usual little chameleon-type sleek reptiles. These could sit up like a woodchuck and run a lot faster. Only grew to about 30 inches long and most were shorter than that.

[...]

British soldiers used to try to tame them and keep them around their tents, saying they ate all the fleas and bugs.

Infantry fire was collective fire

Tuesday, April 9th, 2019

While looking toward a 600-meter lightweight general-purpose cartridge, Emeric Daniau traces the history of individual weapons and notes how their role has changed:

Against large bodies of troops moving in compact formations (as in, for example, the Transvaal campaign), more than 50% of firefights occurred at what we now call “long range” (between 900 m and 2100 m); only 25% occurred at ranges shorter than 900 m (Figure 2).

Engagement Distances 1880-1900

According to J.B.A. Bailey, in the sixty years preceding 1914, artillery fire produced less than 10% of all battle casualties, the remaining 90% fell to small arms (mostly individual weapons), whose range and accuracy had come to rival those of artillery. This estimation is supported by medical and after-battle reports available from that era.

But the introduction of shells loaded with high-explosives (instead of black-powder) around 1890, the invention of reliable impact fuses, the development of rapid-firing guns like the famous French 75 mm Mle 1897 (with an oleo-pneumatic recoil-absorbing mount) and mathematic models for direct and indirect fire solutions (increasing dramatically the hit probability of long-range gunnery) during the same period radically changed the way armies were fighting, and it was anticipated (in 1901, long before WWI) that artillery fire could produce as much as 40% to 50% of overall casualties in future Europeans conflicts.

[...]

WWI saw (indirect) artillery fire replacing (direct) long-range small arms fire in its battlefield effectiveness and this trend continued well after the end of the war. During WWII, small-arms fire including individual weapons and machine guns) produced no better than 2/3 of enemy casualties (when fire support was lacking) and sometimes even less than 1/3. With effective long range fire achieved by HE effects (artillery, tanks and planes), there was a huge pressure to reduce the practical range of weapons (or at least, no need to try to increase it) in order to increase still further the practical RoF.

[...]

In the US, the experience of infantry engagements during WWII and the Korean war (both high intensity wars) was reviewed and the famous “Hitchman” report concluded that since most (~90%) infantry engagements occured at a maximum range of 300 yards (274 m) and hit effectiveness with US M1 Garand rifle was “satisfactory” only up to 100 yards (91 m), a way to increase the individual weapon overall effectiveness (up to 300 yards) was to reduce the bullet and cartridge weight and use a pattern dispersion” principle (controlled burst fired in full-auto mode) to compensate for human aiming errors.

“3. To improve hit effectiveness at the ranges not covered satisfactorily in this sense by men using the M-1 (100 to 300 yd), the adoption of a pattern-dispersion principle in the hand weapon could partly compensate for human aiming errors and thereby significantly increase the hits at ranges up to 300 yd.” (conclusion of the ORO-T-160 report).

It should be stressed that for the authors of the ORO-T-160 report, semi-auto fire was to be used only at short range (less than 100 yards), and “pattern-dispersion” full-auto fire reserved for ranges longer than 100 yards, the opposite of the current thinking of the effectiveness of full-auto fire and an indication that there could be some difference between the concept of “pattern dispersion” and the real realisation as found in current assault-rifles.

The addition of a toxic agent to the bullet (to increase the lethality) was also proposed.

The parallel work on a small-calibre, high velocity (SCHV) cartridge, using a 5.56 mm bullet launched at a very high velocity (1030–1200 m/s) indicated that a large reduction in ammunition weight and recoil could be achieved without decreasing hit probability or incapacitation capability against dismounted soldiers.

Before the Hitchman report, infantry fire was mostly considered as a form of “collective fire”, but after WWII infantry fire effectiveness was often considered only from the point of individual fire, aimed at individual targets, and “collective fire” was replaced by MG fire.

Adapt quickly to the new rules

Tuesday, April 9th, 2019

I wasn’t aware of Selco — even though “Selco is a household name in prepping and survival circles” — but commenter Space Nookie informs me that the founder of the SHTF School has a new book out, The Dark Secrets of SHTF Survival: The Brutal Truth About Violence, Death, & Mayhem You Must Know to Survive:

He survived the Balkan War in a city with no power, no running water, and no supplies. For a year, he and his family fought every single day for bare subsistence. Over the years since the war, Selco has written nearly a quarter of a million words of memories, articles, and advice. This book is a collection of his darkest moments. The first thing you must do when disaster strikes is to adapt quickly to the “new rules” that apply when the SHTF. And to do that, you need to know what it’s like so you won’t be shocked…frozen…paralyzed by the atrocities taking place right in front of you. This book is Selco’s version of tough love. There’s nothing watered down about it. It is a collection of stories, memories, and articles he has documented over the past decade. He has revisited those horrible days to give us the reality check we must have. It’s a glimpse into the day-to-day events of the SHTF. It is smelly. It is dirty. It’s dark and brutal. It’s REAL. It is all the stuff that Selco rarely talks about because the memories are so ugly.

Sounds delightful.

Every American seems to think he has three natural gifts as a birthright

Tuesday, April 9th, 2019

Every American seems to think he has three natural gifts as a birthright — although Dunlap’s list is not exactly the same as I’ve heard from other shooting instructors:

He can play poker; he can carry his liquor; and he can shoot.

And it takes sad experience to convince him that practice plays quite a part in handling all three.

Hands and eyes are not interchangeable accessories

Monday, April 8th, 2019

Dunlap had some basis for his concerns about thieves in Egypt:

From association with a couple of explosive experts I had learned a little about delousing dangerous items but I was always careful not to do any wild experimenting with unfamiliar numbers. I want to watch somebody else tear them down first. Hands and eyes are not interchangeable accessories.

A 24-hour guard was kept on this dump but my main worry was keeping the guards scared enough so they would leave the stuff alone. So help me, though, a guy stole a 14-pound Teller mine once, and we never did find it, even though we broadcast promises not to do anything to him if he would only return it. It was set for around 500 pounds pressure, so he probably could not hurt himself without a lot of effort, but some of the stuff we had I was afraid to even lift myself, to move it out of the way.

[...]

Due to the small number of targets and the large number of men we had to handle, the range had to be in use every minute of daylight, which made it hard on the range officer and sergeant, as one of us had to be there at all times.

We would plow out there at dawn in whatever vehicle we could get hold of with a sufficient supply of ammunition to start the day’s firing. We either had to take a case in with us at night for the morrow’s use, leave it in the range shack back of the butts, or detour by our dump and pick it up in the morning. Occasionally we would leave it in the shack, and an Arab with a camel cleaned us out one night. The shack was of corrugated galvanized steel, door and all, the steel running up to within about a foot of the edges of the roof on the sides, about eight feet from the sand, but our robber went in the opening and removed two cases of loaded ammunition and a case or so of empties. He did not bother the padlocked door though a good kick would open it from either side. To get a better picture of his feat, go through a transom, get a 1,500-round case of .30-06 ammunition and put it through the transom and climb back, not standing on anything except the edges of the door panels while lifting and lowering the box.

What could you do to affect British policy, strategy, tactics and equipment?

Sunday, April 7th, 2019

Anthony Williams has written an alternative-history sci-fi book, The Foresight War, which sounds like something I just might have to get:

What if you went to sleep as usual in 2004 and woke up in 1934? What if you had vital knowledge about the forthcoming Second World War, and could prove that you came from the future? What could you do to affect British policy, strategy, tactics and equipment? How might the course of the conflict be changed?

And what if there was another throwback from the future — and he was working for the enemy?

The novel follows the story of these two ‘throwbacks’ as they pit their wits against each other. A very different Second World War rages across Europe, the Mediterranean, Russia, the North Atlantic and the Pacific, until its shocking conclusion.

[...]

I started to write The Foresight War in order to put down on paper — and thereby exorcise — thoughts which had been buzzing around in my head for years concerning the Second World War. As my primary interest is in military technology, ideas about how this aspect of the war might have developed differently formed the core of the novel. However, in order to turn these concepts into fiction the book clearly had to contain more, so I spent a lot of time researching the tactics, strategies, geography, events and key personalities. The structure of the novel was determined by the principal historical areas and phases of the conflict, as I did not want to depart too much from these. Once the scene was set, the story to a great extent wrote itself, occasionally veering off in directions I hadn’t expected. The main problem was the conclusion, which I didn’t decide on until just before I started the final chapter.

[...]

To sum up: if you are interested in the “what ifs” of World War 2, with particular emphasis on technology and tactics, you will probably enjoy this book. If you’re more interested in how being thrown back into the past might affect the personalities involved, you probably won’t.

As direct and open as Americans in their dealings

Sunday, April 7th, 2019

The New Zealand division was just about the best infantry outfit in the British Eighth Army, Dunlap explains, and was used all the way from Alamein to Tripoli:

The Maoris, or native New Zealanders formed one large battalion of the Division. They are a Polynesian race, similar to our Hawaiians, and are accepted as complete equals by the New Zealanders of English origin. There is absolutely no color bar whatsoever, and intermarriage is very common between the races. Education is compulsory, therefore all get the same start in life on that score. The Maoris, generally pronounced “Mowries” are as direct and open as Americans in their dealings. They come all sizes and cannot be typed. Some are tall, aquiline-featured, others squat, oriental-faced. Some are almost black, others almost white.

The stories of the wars in the early days between English colonists and Maori warriors read like tales of the days of chivalry. Once a British commander retreated from a battlefield rather than continue fighting and destroy a Maori force who had only hand weapons but who formally invited the English to fight it out. In New Zealand for once England came up with the unbeatable colonization formula — get ‘em to join you. So now if a Maori does not like his taxes, he is stuck; the tax collector is probably a Maori too.

Shooting did not bother the skulking prowlers

Saturday, April 6th, 2019

In Egypt, every outfit more-or-less guarded its own area and shops, Dunlap explains — not against the Axis, but against the Arabs:

At that they did dismantle and steal a disabled Grant tank once. A Wog could and would steal anything he could lift or get a camel to carry. Tires and food were worth their weight in money in the Egyptian markets, so they were constantly watched. Shooting did not bother the skulking prowlers at all, unless the bullet connected.

Provide room for a long ogive

Friday, April 5th, 2019

Anthony Williams explains the importance of bullet shape:

A very basic refresher: the rate at which a bullet slows down in the air is determined by the ballistic coefficient; the higher the BC, the lower the velocity loss and the further the bullet will fly. That is, “other things being equal” — always an important qualification because there are so many variables. The BC is calculated from two other numbers, the sectional density (SD) and the form factor (FF). The SD is simple to calculate as it measures the bullet weight compared with the calibre; a 100 grain 30 cal bullet will have half the SD of a 200 grain 30 cal. The higher the SD, the better for long-range performance. The FF measures the shape of the bullet; it is not simple to calculate and its effect varies with velocity, but at a basic level it’s really common sense — a bullet with a long pointed nose, or ogive, is likely to have a better FF than one with a blunt ogive, especially at supersonic velocities. It’s the FF that I want to talk about.

I looked around for examples of bullets which are as alike as possible except in their shape in order to illustrate the importance of the FF, and found the two .50 cal bullets from Barnes Bullets shown on the screen. They are both made from solid brass to the same standards and both weigh the same — 750 grains. Barnes helpfully provides the BCs for this pair, so it’s a simple matter to feed the data into a standard ballistic calculator in order to work out the effect of the different shape. The results of this are interesting.

Barnes .50-Caliber Bullets

There are various ways of assessing the effective range of ammunition, one of them being the impact energy of the bullet on the target. The long bullet shown here has the same impact energy at 2,000 metres as the shorter bullet has at just over 1,400 metres. By this measure, that amounts to a 40% increase in effective range from using the long bullet rather than the shorter one — and it’s free! No extra ammunition weight, no extra recoil. The catch is, of course that the shorter bullet has been designed to keep within the official maximum overall length of the .50 Browning cartridge, so that the ammunition can be loaded into magazines and will function in gun actions; loaded with the long bullet, the cartridge can only be used in specialised single-shot rifles.

This problem of a short cartridge overall length, which prevents the most efficient, low-drag bullets being used, applies to at least some degree to all NATO rifle and machine gun ammunition. The long-range performance of all of these rounds is inherently limited by their inability to use such bullets. Their bullets all have quite short ogives which results in poor FFs and therefore poor BCs. The only way to improve the BC of bullets for these rounds is to use heavier bullets to increase the SD, but that puts up ammunition weight and recoil and results in a lower muzzle velocity and steeper trajectory.

NATO Small Arms Ammunition

The .338 Lapua Magnum has become the international standard long-range sniping round, but it was designed for bullets of up to 250 grains and doesn’t allow enough space for well-shaped versions of the 300 grain bullets which are becoming increasingly popular. It is interesting that General Dynamics selected the relatively obscure .338 Norma Magnum for their Lightweight Medium Machine Gun. I have heard various reasons why they chose the Norma round but one is incontrovertible; the shorter Norma case permits the use of bullets with a longer ogive, giving it the potential for a superior long-range performance.

The next slide is where things get really interesting. The standard 7.62mm NATO cartridge and its M80 bullet are shown at the top. The other pair illustrate one of my favourite examples of the merits of unconventional thinking. The Voss bullet was designed by a German ballistician, Dr Gunther Voss, in the early 1950s, when he was working for the Spanish CETME organisation. He wanted to develop a cartridge which combined a long range with a recoil light enough to permit controllable automatic rifle fire. He reasoned that for the recoil to be kept low, the bullet would have to be as light as possible, but as that would give it a poor sectional density, to achieve a long range would require giving it the best possible form factor. So his bullet is made of solid aluminium with a copper jacket over most of its length. It actually weighs 106.5 grains, which is less than the stumpy little .30 Carbine bullet, but the shape is so good that the BC is only a little lower than the 7.62 M80 which weighs 147 grains. Because the bullet is so light, it doesn’t need much propellant to drive it at a velocity comparable with the 7.62, so it uses a smaller cartridge case, saving yet more weight and further reducing recoil.

Bullet Design M80 versus Voss

By the few accounts I’ve found, Voss’s CETME round did what it was designed to do. In effect, it provided 7.62 NATO performance in a package that was similar in weight and recoil to the short 7.62mm Kalashnikov round. One potential drawback was lack of penetration, but it was claimed to be able to penetrate a contemporary steel helmet at 1,100 metres. I suspect that it might not have done so well against thicknesses of material, such as timber. Unfortunately for Voss, by the time it was ready to roll it was 1953 and the 7.62 NATO round had an unstoppable momentum, flattening all rivals in its path. The irony is that the US Army had wanted a long-range, .30-calibre cartridge with a recoil light enough for controllable automatic fire in a light rifle. The Voss design came very much closer to delivering that than did the 7.62 NATO, purely because of the superb shape of the bullet.

In the early 1970s something very similar was tried by the US Army with the 5.56mm FABRL, shown alongside the contemporary 5.56mm M193. FABRL originally stood for Frankford Arsenal and the Ballistic Research Laboratory, but it was later given the sexier meaning of Future Ammunition for Burst Rifle Launch. The aim was to reduce the recoil of the contemporary 5.56mm ammunition to make the rifles more controllable in burst fire. To achieve this the bullet weight was reduced from 55 to 37 grains by making it from steel with a plastic core, yet the much improved FF meant that the BC remained the same. Little more than half the propellant was needed to match the muzzle velocity of the M193 so the cartridge case could be shortened to leave room for the long bullet, and the chamber pressure was so low (39,000 psi instead of 52,000) that the use of an aluminium case became feasible, leading to an overall reduction in cartridge weight of 50%. The trajectory remained the same, but the recoil impulse was reduced by 35% (equivalent to a reduction in free recoil energy of over 60%).

Bullet Design M193 versus FABRL

The lesson to draw from this is not that all bullets should be made of aluminium or plastic — the two I’ve shown are clearly extreme examples — but that a well-shaped bullet gives you options you don’t have with a typical NATO bullet shape. You can keep the bullet weight the same, and enjoy an improved long-range performance; or if you don’t need to extend the range, you can reduce the bullet weight while still keeping the same BC as the NATO bullet, thereby reducing cartridge weight. If you reduce the bullet weight, you have another choice: you can leave the propellant load and cartridge case the same, and enjoy a higher muzzle velocity and flatter trajectory; or you can keep the MV the same and reduce the propellant load and size of the cartridge case, as in both examples I’ve described, gaining further reductions in recoil and ammunition weight. These are all great choices to have, but you only get them if you adopt a very well-shaped bullet, which means that the cartridge specification has to provide room for using bullets with a long ogive.

In case you didn’t already know — or didn’t deduce it from context — an ogive is a roundly tapered end, like the “point” of a bullet:

In ballistics or aerodynamics, an ogive is a pointed, curved surface mainly used to form the approximately streamlined nose of a bullet or other projectile, reducing air resistance or the drag of air. In fact the French word ogive can be translated as “nose cone” or “warhead”.

The traditional or secant ogive is a surface of revolution of the same curve that forms a Gothic arch; that is, a circular arc, of greater radius than the diameter of the cylindrical section (“shank”), is drawn from the edge of the shank until it intercepts the axis.

If this arc is drawn so that it meets the shank at zero angle (that is, the distance of the centre of the arc from the axis, plus the radius of the shank, equals the radius of the arc), then it is called a tangent or spitzer ogive. This is a very common ogive for high velocity (supersonic) rifle bullets.

The sharpness of this ogive is expressed by the ratio of its radius to the diameter of the cylinder; a value of one half being a hemispherical dome, and larger values being progressively more pointed. Values of 4 to 10 are commonly used in rifles, with 6 being the most common.

Another common ogive for bullets is the elliptical ogive. This is a curve very similar to the spitzer ogive, except that the circular arc is replaced by an ellipse defined in such a way that it meets the axis at exactly 90°. This gives a somewhat rounded nose regardless of the sharpness ratio. An elliptical ogive is normally described in terms of the ratio of the length of the ogive to the diameter of the shank. A ratio of one half would be, once again, a hemisphere. Values close to 1 are common in practice. Elliptical ogives are mainly used in pistol bullets.

Missiles and aircraft generally have much more complex ogives, such as the von Kármán ogive.

Everything happens in Egypt

Friday, April 5th, 2019

Dunlap managed to fit in some rifle practice in Egypt:

Three hundred meter matches were lined up, so we practiced at 300 yards on standard British short range targets most of the time. The scoring rings are fairly close to those of our “A” target, but that is all. This is the camouflage target—top half a dull blue, bottom sand color; top half of bull is black, bottom, gray. It symbolizes a man looking over a skyline; the black is his head, in helmet, the gray his face, the blue the sky, the sand or buff color the earth. You go gradually blind looking at it; or rather, for the bull. I have to admit it is a more practical paper mark than our black and white job, but it is not nearly as much fun to shoot at! That little half-moon of black is hard to see even in bright light. Paradoxically, twice at Abassyia we had to hold up shooting until a dense fog cleared. Everything happens in Egypt.

Once we shot on 300-meter targets, at 300 meters, and on one string of six shots I set myself a high score of 56 out of 60. This is impossible, as the gun, ammunition and holding were not that good. One of those freak groups which pop up every once in awhile. Four consecutive strings like that would break the world record by 14 points, or maybe it is 17.

They are by no means jungle savages

Thursday, April 4th, 2019

The war brought all kinds of people together, Dunlap explains:

Sudanese are rated higher than the paler Arabic Egyptian by the Europeans in the Near East, and they are popular as waiters and general servants. As a people they are much cleaner and less diseased, and are a prouder race. Some have become wealthy business men in the cities. They are by no means jungle savages. The British respect them highly and rate them almost on a par with the Ghurka as fighting men. As Kipling wrote of “Fuzzy-Wuzzy,” he was the only man who ever “broke a British Square.” His hair is not so kinky and he does not wear it in the fuzzy-head fashion any more. The English have educated them as best they could and all except the back-country boys could read and write Arabic. One young fellow came up to me with an English-language newspaper once to ask the meaning of the word “counter-attack” — he was reading the news to the rest of his gang. Turned out he could read, write and speak Arabic, French and English, but had trouble with the English.

I do not know if their national sport is still killing lions with spears but they know how to handle rifles. Both the Arabs and the Sudanese seemed to understand weapons very well. We used to call one of them over every once in awhile and give him a gun of some sort to look over while we looked him over. I remember once an M1 rifle came through somehow and we let some of the natives see it. One of them snapped back the operating handle, looked in the chamber and receiver, worked the safety a couple of times, asked what the gas cylinder was and handed it back. He knew how it worked, that was all. No awe, no surprise, no nothin’, except he would like it a little lighter; so would I.

When a batch of American Negro soldiers came through I brought several down to the warehouse to pick up their rations and witness their reaction to the Sudanese and vice versa. The Americans went pop-eyed at the rather sinister-looking boys and definitely disclaimed all relationship on their part. As one of them put it, “They may belong to mah race, but thazzall! I ain’t like them!” One of the Sudanese came to me and asked how come. I told him in Arabic that they were Americans whose ancestors had been Africans. He said “Why?” That being involved, I forcefully requested him to start throwing the Spam on the truck.