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Earlier this week, Business Insider released an article written by Christian Lowe entitled “ 6 weapons the US military should bring back from the dead“ with a very self-evident, but interesting premise. However, the weapons (all firearms, oddly) that the article outlines are very poor choices, so today I want to talk about why these choices are so poor, and maybe suggest some better alternatives of my own. Let’s take it point by point, quoting his text and following that with my responses:

Today on an extra special episode of Historical Intermediate Calibers, we’ll be taking a look at one of the most controversial experimental military rounds, one that many believe should have become the standard for the Western World at the beginning of the Cold War. That round is the .280 British, also known as the 7x43mm, and beginning in 1947 it competed head-to-head against the caliber that eventually became the 7.62 NATO in trials to become the standard infantry small arms caliber of the free world. The .280 British has, in the almost 70 years since its invention, become one of the great “might-have-beens” of the small arms ammunition world. Many small arms enthusiasts wonder how firearms history might have been changed if this brilliantly designed British 7mm round had been adopted by NATO instead of the overlarge and too-powerful US-designed 7.62mm.

In a previous article on TFB, we compared a Mauser 712 Schnellfeuer to a Glock 17 with an auto sear, and along the way discussed how very limited the usefulness of the modern machine pistol is. Fully automatic pistol-sized weapons have been around for over a hundred years, but they’ve only ever seen limited use in specialist roles, with their adoption and then subsequent abandonment coming seemingly in waves as departments and forces pick up the concept and then discard it upon learning how impractical the weapons are in actual use. The history of machine pistols is fascinating, and those who are interested can follow the link to a podcast I participated in on the subject to learn more.

At this point we’ve looked at the data for seven intermediate calibers currently on the market, each of which is – one way or another – influencing the discussion around the question of what next generation military rifle caliber will be. Those rounds were: The 5.56mm NATO, the 7.62x39mm Soviet, the 6.8x43mm SPC, the 6.5x38mm Grendel, the .300 AAC Blackout, the 7.62×40 WT, and the .25-45 Sharps. Initially, I intended for this series to be limited to just these seven, and I picked them as a cross section of different concepts and schools of thought regarding the intermediate caliber problem. Now, however, I have decided to expand this discussion to other calibers, including the latest developments outside the West. I figure I’ll just handle the extra clunk this introduces by breaking up the final comparative discussion into segments, that way all the data is presented clearly, and there are more posts for my readers to chew on. Everyone is happy.

Back in May, Chris Baker released these three videos on DA/SA handguns for the LuckyGunner YouTube channel. They are all of the same high standard of quality I’ve come to expect from Chris, so I recommend my readers watch all three of them before continuing:

Since we know that gunshot wounds follow physical laws – Newtonian mechanics, specifically – we can use physical quantities to describe what happens to a bullet when it enters a fleshy target. In a previous post, we were introduced to three physical quantities: Force, work, and kinetic energy. To see how these apply to a gunshot, let’s use the example of a hollow point bullet as it impacts and penetrates 10% ballistic gelatin.

This is one of those posts I’ve been meaning to get to for a while, but haven’t really felt the urge to write.

What if there was a caliber that was suitable for everything from coyote to brown bear, kicked less than your whitetail gun, fit in a micro-length (2.25″/58mm) action, and cost a quarter a round to shoot? That would be a pretty awesome caliber, wouldn’t it? It turns out that this caliber might already exist, if the industry can fulfill its potential: It is the Russian 7.62x39mm caliber used by the infamous AK-47 rifle.

It’s no good to discuss how firearms work without also giving the context surrounding the firearms themselves. With that said, let’s talk about the AR-15, its copycats, competitors, and relatives. Together these rifles share space under the loose umbrella of black rifles, a term which references the use of lighter and more durable black polymer gunstocks in place of traditional wood, something that became common from the 1960s onward in military firearms design. Today the term simply means any modern military rifle, or any rifle patterned after a modern military rifle, the two most common of these by far being the AR-15 and AK types. For the purposes of this article, we’ll focus on the AR-15, but much of what we’ll talk about will be applicable to any black rifle.

One thing that seems apparent from the ARDEC presentation on the CTSAS program is the excessive capability and weight of the 6.5mm CT ammunition, as well as its use of lead-cored projectiles as opposed to more modern (and less dense) EPR-type projectiles. Further, the 6.5mm configuration explicitly uses the same case as the 7.62mm CT round, to allow for shorter development times. These facts together indicate that the 6.5mm CT round demonstrated in the ARDEC presentation is not well optimized for minimum weight. For this post, we’ll create an estimate of a new, lighter round that still should be powerful enough to replace both 5.56mm and 7.62mm as a universal caliber. As mentioned in the previous post, we’ll call it the “LW 6.5mm CT” to differentiate it from ARDEC’s 6.5mm CT round.

Recently, I wrote an editorial regarding the LSAT/CTSAS team’s NDIA presentation on their 6.5mm cased telescoped carbine and machine gun concepts. There was a lot to say about the history of Army programs and the pitfalls facing that team, but today I want to get down to brass tacks and explore the weight savings and/or penalty of issuing to the infantry platoon the 6.5mm CT cartridge Phillips’ team proposed. Like in my November of 2013 article on the general purpose cartridge concept, I will be using the loads reported in the paper The Modern Warrior’s Combat Load, released in 2003. That paper is a little dated, unfortunately, but it’s the most comprehensive survey of the platoon’s loadout of which I am aware.

When a bullet flies through the air, forces called “drag” are exerted upon it. These forces slow down the bullet as it flies, but they don’t act the same way on every bullet. While the subject of aerodynamics is extremely complex, one way to account for differences in bullet drag that is commonly used in the world of small arms is the “ballistic coefficient”.

Beginning in the last decade of the 19th Century, the French government began work on the next great advancement in infantry small arms technology: The selfloading rifle. By 1916, after the outbreak of World War I, they had produced what many consider the most advanced rifle of its time: The Meunier A6 Carbine.

The National Defense Industry Association has released the PowerPoint presentations from 2016 Armament Systems Forum, including  Kori Phillips’ update on the Cased Telescoped Small Arms Systems (CTSAS) program, which is the successor to the well-known Lightweight Small Arms Technologies program (LSAT). Of special note in the presentation is the program’s decision to explore (and, to an extent, promote) the 6.5mm caliber as a viable option for CT configuration next-generation ammunition. There is quite a lot that could be discussed about this, but I’d like to focus on two pieces of information given to us by the presentation, those being the effective ranges  and the weight cited for the 6.5mm CT ammunition, shown by the slides below:

In a recent post, I discussed four ballistics myths that I’ve heard over the years, and why they are just that – myths. One of these was the myth that the momentum of a projectile is equivalent or otherwise indicative of the stopping power of that projectile. I have for several years now been arguing that it is not, and the subject comes up again and again in my comments, so it’s high time I directly addressed it in a post. The short answer is “no”, as I wrote in “4 Ballistics Myths”: