NS Military Worldbuilding Thread No. 12

[Dayganistan]

If someone wanted to squeeze more velocity or range out of a recoilless gun couldn't they do so with rocket assisted projectiles? For example something around the size and weight of the Carl Gustaf but it fires SPG-9 rounds.

[Gallia-]

Rockets are inaccurate and you would lose a large amount of the benefits of spin-stabilization.

That said this isn't a particularly big problem if you're aiming at a literal house, or you're not looking at any huge range increases.

A RAVEN gun has most of the advantages of a conventional cannon with the disadvantage of being slightly bigger and harder to balance. This is a relative non-problem for a armored vehicle.

But it turns out that Stryker has enough mass in its ass to take a normal XM35.

I might draw a RAVEN equipped Black Knight ARCV.

[Grand Indochina]

Hello, hello !

1) Can someone tell me the difference in performance between the 6.5x50mmSR Arisaka and the 6.5x55mm Swedish ?

2) Can I use a different cartridge for my rifle, provided that this cartridge is different from the one the gun is designed to use ?

Let’s say I have a FN SCAR, which is chambered in 7.62x51. What will happen if I switch to the 7.62x39 instead ?

Thank for reading !

[Dayganistan]

Hello, hello !

1) Can someone tell me the difference in performance between the 6.5x50mmSR Arisaka and the 6.5x55mm Swedish ?

2) Can I use a different cartridge for my rifle, provided that this cartridge is different from the one the gun is designed to use ?

Let’s say I have a FN SCAR, which is chambered in 7.62x51. What will happen if I switch to the 7.62x39 instead ?

Thank for reading !

6.5 Arisaka is a very underpowered cartridge. Significantly lower muzzle velocity and energy than 6.5 Swedish.

To switch a 7.62 NATO rifle to 7.62x39 you'd need a new barrel, bolt assembly, and magazine.

[Gallia-]

Just load the cartridge arbitrarily high lol. The Arisaka action is, like most Japanese mechanical things, notoriously understressed, so you'd probably explode a Swedish Mauser before you explode a Arisaka.

e: CIP pressure is around 40k PSI for a 6.5 Arisaka but you can probably load it to 55k PSI and see not much of an issue.

OTOH the gun might spontaneously disassemble itself if you're constantly shooting magnum rounds I guess idk.

[Austrasien]

Sorry about the vagueness-- I was referring to radar jamming, thus removing the countermeasure's turret to track incoming projectiles (assuming said countermeasure I know very little about uses something along the lines of MMW radar, though it is just as likely to use infrared tracking.)

I am mystified as to where you expect to find a MMW guided laser cannon. At most a laser weapon would receive cueing information from a radar, it would still have its own optical tracking system for actually pointing the beam at the target, and so would not be completely dependent on a radar.

[Sevvania]

Let’s say I have a FN SCAR, which is chambered in 7.62x51. What will happen if I switch to the 7.62x39 instead ?

It isn't a 1:1 replica or a real "conversion," but may be in your interest if you're considering a SCAR in 7.62x39mm:

https://guns.fandom.com/wiki/CS/LR17

[Cossack Peoples]

I am mystified as to where you expect to find a MMW guided laser cannon. At most a laser weapon would receive cueing information from a radar, it would still have its own optical tracking system for actually pointing the beam at the target, and so would not be completely dependent on a radar.

Look, the system I've been talking about is invented by someone who didn't give many details except superfluous tidbits so I'm largely inventing what the thing could be. And frankly, you wouldn't be in so much disbelief about something so foolhardy as MMW-tracking laser cannons if you knew that the person who made this laser system also operates massive 118,000 tons displacement battleships, a completely nonexistent submarine force, and fighters that are powered by a fusion reactor and have unlimited range (oh, and go Mach 5+ as a cruising speed).

[Austrasien]

Look, the system I've been talking about is invented by someone who didn't give many details except superfluous tidbits so I'm largely inventing what the thing could be. And frankly, you wouldn't be in so much disbelief about something so foolhardy as MMW-tracking laser cannons if you knew that the person who made this laser system also operates massive 118,000 tons displacement battleships, a completely nonexistent submarine force, and fighters that are powered by a fusion reactor and have unlimited range (oh, and go Mach 5+ as a cruising speed).

If you assume it's exactly as you are describing it, it just isn't a practical weapon concept. If you assume more generously it would work as a laser weapon would likely work - the MMW radar cues the laser head which tracks the target and blasts it - radar jamming will only degrade its ability to find targets.

[The Akasha Colony]

I am mystified as to where you expect to find a MMW guided laser cannon. At most a laser weapon would receive cueing information from a radar, it would still have its own optical tracking system for actually pointing the beam at the target, and so would not be completely dependent on a radar.

Look, the system I've been talking about is invented by someone who didn't give many details except superfluous tidbits so I'm largely inventing what the thing could be. And frankly, you wouldn't be in so much disbelief about something so foolhardy as MMW-tracking laser cannons if you knew that the person who made this laser system also operates massive 118,000 tons displacement battleships, a completely nonexistent submarine force, and fighters that are powered by a fusion reactor and have unlimited range (oh, and go Mach 5+ as a cruising speed).

It seems like it would be easier to just link this concept rather than play telephone, but either way it sounds like the concept is unworkable.

[Grand Indochina]

6.5 Arisaka is a very underpowered cartridge. Significantly lower muzzle velocity and energy than 6.5 Swedish.

To switch a 7.62 NATO rifle to 7.62x39 you'd need a new barrel, bolt assembly, and magazine.

Just load the cartridge arbitrarily high lol. The Arisaka action is, like most Japanese mechanical things, notoriously understressed, so you'd probably explode a Swedish Mauser before you explode a Arisaka.

e: CIP pressure is around 40k PSI for a 6.5 Arisaka but you can probably load it to 55k PSI and see not much of an issue.

OTOH the gun might spontaneously disassemble itself if you're constantly shooting magnum rounds I guess idk.

Thank for answering, Dayganistan, Gallia-.

It isn't a 1:1 replica or a real "conversion," but may be in your interest if you're considering a SCAR in 7.62x39mm:
(Image)
https://guns.fandom.com/wiki/CS/LR17

Thank for the advice, Sevvania.

[New Aeyariss]

How much more costly is the hydropneumatic suspension for a tank, compared to say, torsion bar?

[Triplebaconation]

fighters that are powered by a fusion reactor and have unlimited range (oh, and go Mach 5+ as a cruising speed).

Badass. Thanks for reminding us how lame "realism" is.

[Cossack Peoples]

fighters that are powered by a fusion reactor and have unlimited range (oh, and go Mach 5+ as a cruising speed).

Badass. Thanks for reminding us how lame "realism" is.

Let's not forget the other end of the spectrum who has a religious attachment to cold-war interceptors and supersonic bombers, the latter of which gives my nation a pretense to still operate purpose-built interceptors and multitudes of otherwise superfluous SAM systems.

[Hrstrovokia]

What are opinions on Israeli tank ammunition? I saw this article about the Israeli company Elbit making 125mm tank ammunition for possible Indian orders. It's designed for the T-90, T-80 and T-72 MBTs so presumably fits the autoloader and gun in all 3 types.

I've looked up the M711/8 (MK2) round which is APFSDS-T but I can't find exact RHA values. So my question is, how good is Israeli tank ammunition? Would it be better than a similar Russian round? Would it be better than Mango or Lekalo?

[Danternoust]

I would assume that the Israelis have an edge in chemistry and metallurgy, translating into having propellants with a more uniform burn and superior precise machining of tungsten rod penetrators. The Israelis could have additional technical advantages I'm not able to speculate on.

Apparently a triple heavy target (comprised of less overall RHA) is more difficult to penetrate than a single heavy target (equivalent to an old fashioned Korean war-era heavy tank). https://en.wikipedia.org/wiki/NATO_targets

[Gallia-]

What are opinions on Israeli tank ammunition? I saw this article about the Israeli company Elbit making 125mm tank ammunition for possible Indian orders. It's designed for the T-90, T-80 and T-72 MBTs so presumably fits the autoloader and gun in all 3 types.

I've looked up the M711/8 (MK2) round which is APFSDS-T but I can't find exact RHA values. So my question is, how good is Israeli tank ammunition? Would it be better than a similar Russian round? Would it be better than Mango or Lekalo?

Length is the biggest factor in LRP penetration and I doubt the Israelis have anything substantial to offer to that table since the Russians have probably maxed out the size of the penetrator.

There are some novel penetrator designs but there's no real reason to think that these would be used in an export ammunition. Also they wouldn't substantially improve base penetration (they might reduce it though) except against exotic forms of armor.

The real advancement here is that the Israelis can provide ammunition that previously required going through the Russians.

[Danternoust]

Length is the biggest factor in LRP penetration

I would think ballistics. are the biggest factor in LRP penetration.

The real advancement here is that the Israelis can provide ammunition that previously required going through the Russians.

India is not an insignificant country, they do have substantial industrial capacity.

[Gallia-]

lol

[Purpelia]

When it comes to penetration ignore what your concubines tell you. Size does matter.

[New Vihenia]

So basically one cannot penetrate more than what it has.

[Gallia-]

So basically one cannot penetrate more than what it has.

And the best penetrator is a solid monobloc, yes.

Cutting a rod diagonally might work but that has its own problems. Any sort of penetrator increases with a cut rod just results from a longer penetrator (you slide it backwards so it's physically longer), so it's a bit of a tautology; and it will require sheathing or cladding; I guess if you're hard up for the literal physical metals it's something to consider.

A cruciform shape might slightly increase penetration over a cylinder in certain armors though since it concentrates the same energy in a smaller area, but most people aren't rolling around with solid walls of RHA, so it's not really an expectation that you'd take advantage of. The main benefit would be it acts like an I-beam (there are also triform and H/I-beam shape penetrators) and resists bending/snapping. I like H-rods because of their resistance to lateral flexion and snapping so they might potentially offer something over ordinary cylindricals in penetrating heavy ERA, but they're really hard to fabricate since most rods are just made by spinning ingots on lathes.

You'd need to dig out the H-rod from the ingot by machining and that would require a lot more work time.

Maybe issue it as a special ammunition or something, like the WW2 76mm HVAPs, which is what I think Dumbla does last time I wrote a blurb about this sort of thing (c. 2014).

[Arroyo-Abeille]

lol

What? Out of the top 10 they rank 30th. And In heavy manufacturing (also the one that matters lol) they rank an astonishing 56th. Truly the markers of a major industrial power.

[Gallia-]

I'm sure India can produce tons of ammunition but that's not important.

I'm loling because he said velocity was the biggest part of penetration.

The difference between 1,500 m/s and 2,000 m/s for any given heavy metal penetrator is less than the difference between 1,000 m/s and 1,400 m/s by a good order of magnitude.

[Danternoust]

Roughly every tenth of a second, an object is accelerated downwards by one meter per second. This compounds, and after 300 meters of distance for a longrod with a muzzle velocity of 1.5 km/s it will have drifted downward by approximately 3 meters, ignoring initial gunsight errors.

If my math is right.