Crowdsourcing my R&D

Rat, как мы выяснили почти год назад, возможности Минервы по запуску вещей в космос не превышают пары пусков в год с весьма скромной полезной нагрузкой. И до машин фон Неймана тут ещё не дошли и едва ли дойдут в военное время.

С машинами фон Неймана вопрос не столько в возможности машины собирать себе подобное (в "Мираже" упоминается автономная сборочная линия, на которой, судя по всему, собиралась броня вроде той, которую использует Тензин), а в добыче необходимых материалов. Если нести все с собой, то какой смысл собирать что-то на месте? Если пытаться добыть все нужное на месте, то возникают вопросы геологоразведки и того, что залежей критичных металлов вообще нет поблизости.

А, да, и Минерва из принципа не использует ядерные технологии.

From the discussion above: by von Neumann machine we mean not a single vehicle or production unit but a whole system that includes resource harvesters, production facilities and so on. The key trait of von Neumann machine is it's complete automation by an AI.

Electromagnetic Rail Anti-Material Rifle 
This is the heavy weapon system known as the ERAMR (Electromagnetic Rail Anti-Material Rifle), or by the troops that use it as "The Big One," although it is disputed if this is due to the size of the weapon, the damage caused by impact, or the massive power requirements.

When carried by standard infantry, the weapon requires a crew of two. One person carries the six foot long weapon itself, which fortunately folds at the base of the barrel for ease of transport. The other transports the ammunition and the massive battery packs, each of which measures 25cm long and  15 cm wide. These packs are disposable and cheap batteries, but the weapon can be used with larger, higher capacity batteries. As such, the other, more common means of deployment is with a suit of power armor. Soldiers who use it with suits of powered armor must use specially modified armor to cope with the ridiculous power requirements.

Rapid fire can feel natural at first, due to the lack of conventional recoil, but such behavior is drummed out of trainees within the first weeks of training, as taking too many shots too quickly can empty the battery quite rapidly, and leave a soldier in a powered exoskeleton laying helpless on the ground, a frozen metal statue.  However, the ERAMR is functionally identical to other railguns in use, albeit much, much larger.

The unique part of this weapon is the ammunition. The caliber of the weapon (15mm) permits much larger and more complex rounds than can be fired from a standard railgun. The two most common ammo types are CPTP rounds and standard kinetic penatrators. The CPTP (Copper-Plasma Tipped Penatrator) round is made of a hollow tugsten body with a copper head. The hollow space in the body is filled with argon. When the round is energized by the magnetic rails, the argon becomes a plasma, generating a massive amount of heat and pressure. The tugsten body of the round can withstand this pressure, but the impact breaks the thinner tugsten wall between the argon and the copper. This creates a flash of plasma and a molten copper penetrator moving at hypersonic speeds. The CPTP shell is notorious for the purple flashes of argon released on impact, and the massive penetrating power of the copper penetrator has been known to shear through tanks. Indeed, many armored units will flee upon sight of the purple glare created on impact. However, the MRAMR can also fire a variety of more... exotic rounds. Among these are flechette cluster rounds, bolo rounds, plasma burst rounds, and so many more. A large enough barrel for use of SABOT rounds and a powerful enough weapon to fire incredibly heavy projectiles permits a nearly infinite variety of so-called "oddball" custom rounds.

The only downside to the ERAMR other than the size is the massive, twenty-foot plume of smoke and sparks that spews from the barrel on firing. Most ERAMRs are equipped with muzzle breaks, to vent the smoke to the sides, but it is still impossible to fire one in a subtle manner from close range. Due to this, most engagements are from far enough away that the targets cannot easily spot the sniper or return fire.

Do take a moment of your time to format the text you write if it is a long one. A giant wall of text is rather hard to read, especially if it contains a lot of non-common words.

I drew a cartridge for Tenzin's autocannon. I was hasty, but it appears to be a 20x91mm. The total length of a whole cartridge would be 137mm, the same as a 12,7x99 (.50 BMG) cartridge. The projectile is 76mm long. The base diameter is 25,5mm, the shoulder diameter is also 25,5 (straight sides). A conservative estimate of powder capacity is 25 cubic centimeters, compared to 19cc's for the .50 BMG. I can't accurately calculate the recoil because I don't know the total weight of the weapon. However, a .50 BMG firing a lighter bullet at slower speeds from a 13,5 kilogram rifle produces 95 joules (70 foot pounds) of recoil force. I expect Tenzin's main weapon would break a human shoulder if it was fired without powered armor.



My goal for the new cartridge is to reach 1220 meters per second with a 61,5 gram projectile. It would have 45700 joules (33,700 foot-pounds) of kinetic energy at the muzzle. At one kilometer, the projectile has fallen 660 centimeters (260 inches, about 22 feet) assuming a G1 ballistic coefficient of .350 (a measure of how aerodynamic the bullet is, mediocre in this case). At one kilometer, it would still be moving at 396 meter per second (1300 feet per second) and would have 4880 joules (3600 foot-pounds). This does not count an explosive projectile, which are common for the 20mm caliber.



The smaller cartridge shown is a 6.5x51mm, which would be good for general issue. It has respectable power and trajectory, and it's made from a 7.62 NATO casing with a smaller-diameter bullet. Professional shooters with modern rifles commonly use this cartridge to win long-range target shooting competitions. Recoil is mild enough to fire rapidly, power is similar to a 6.5x55 Swedish Mauser: 9g (140gr)  855mps (2800fps) = 3300 j (2440 ft-lbs)

The bullet is fictional, based on the superb Nosler Partition bullet and modified to hunt humans instead of boar. There is an open air cavity in the tip, with a hardened steel cone to penetrate light armor. The copper jacket has a famous barrier that divides the core into front and rear halves. The front is likely to peel backward and fragment, but the rear core is lead with a full copper jacket. If it behaves as I hope it will, the heavy rear core will push the steel cone through armor plates. Damage within 700m is worst, but it remains deadly at 1,000m or longer if you can hit someone. If there is no armor, the weight distribution (heavy rear core, empty tip) makes the entire bullet tumble inside to cut a wide permanent wound.