#Aai

In the comments section of my recent Brief Thoughts article regarding caseless ammunition, there was a discussion about whether the cookoff issues of caseless would also be problem for LSAT-style polymer cased telescoped ammunition. Based on conversations I have had with subject matter experts regarding polymer cased ammunition in general, I noted that a lower cookoff threshold is one of the challenges I would expect CT ammunition developers to face. However, after some back-and-forth in the comments, I decided to contact LSAT/CTSAS program officer Kori Phillips regarding this issue (as it was not something I covered in my three-part interview with her), and she kindly agreed to allow her comments on the matter to be published here on TFB. They are below:

Caseless: The ammunition designer’s holy grail, and the engineer’s worst nightmare. It would obsolete the cartridge case overnight, resulting in cheaper, lighter, and more compact ammunition. Weapons would be able to carry 50, 60, or more rounds in slim, inexpensive magazines, and expel them at a rate of fire much higher than current weapons are capable of – not only because the ammunition is lighter and therefore more could be carried to feed such thirsty guns, but because the extraction and ejection cycles of the weapons themselves could be eliminated.

It looks like it could be back to the future for the US Army, if Textron’s new carbine design is any indication of what’s to come. The company unveiled its latest prototype of a cased, telescoped ammunition-firing rifle at Modern Day Marine 2016 in Quantico, VA, on Tuesday. The rifle, which weighs 8.7 pounds unloaded and feeds from a 20-round magazine, is reported to fire a 123gr 6.5mm bullet at 3,000 ft/s, producing 3,350 J and rivaling the existing 7.62 NATO in energy. Military.com’s KitUp! reports:

In the last episode, we discussed how the most ballistically efficient projectiles are the longest, most slender ones, with the highest sectional density. This naturally leads to the idea of using a super long, rod-like projectile which would in theory have excellent ballistic characteristics… But there’s a problem with that: Unfortunately, modern rifle projectiles are spin-stabilized, and there’s a limit to how long of a projectile can be and still be stabilized by gyroscopic forces in that manner (that limit is about 7 calibers long in theory, more like 6 in practice). This means that to successfully stabilize the longest possible projectile with the highest possible sectional density, another method is needed. The most popular alternative – and the one used in arrows, darts, APFSDS tank projectiles, and today’s topic, flechettes – is fin-stabilization.

In the comments section of  my 6.8mm SPC article last year, I was asked what I thought about future infantry small arms. This is a subject that has dominated my thinking over the past several years, and much of the historical research I have undertaken has been in service to forming a better picture of the current state of small arms and how to improve it.

Project SALVO’s experiments with multiple projectile ammunition did, surprisingly, result in the production of service ammunition. The 7.62mm M198 Duplex round was an attempt to improve the short-range combat effectiveness of the M14 rifle (so far as this author knows, it was never linked for use in the M60 machine gun – ED: Commenter Bud Harton mentions that it was linked for use in the M60, and this has been confirmed by other sources), but the fundamental limitations of duplex ammunition remained, and it was never successful. Eventually, the improved hit probability rifle would be realized in the .22 caliber AR-15, adopted as the M16 before the Vietnam War.