>rifled barrel for a rifle
Good, increases accuracy
>rifles Barrel for a tank
bad
Can someone explain why this is
>rifled barrel for a rifle
>rifled barrel for a rifle
Good, increases accuracy
>rifles Barrel for a tank
bad
Can someone explain why this is
modern tank shells are produced to be aerodynamically stabilized instead of spin stabilized, imparting a spin on such a projectile actually decreases the effectiveness of an aerodynamically stable shell.
Don't shotgun slugs also follow this principle? Sabot slugs, anyway.
yes! they infact do! as they are both smoothbore guns and use sabots as their main penetrative munition
Rifled slugs use this principle. Sabot slugs require a rifled barrel to stabilize. You had it backwards.
neger likke mein anoos
>Rifled slugs use this principle
The rifling on slugs is actually meant to allow the slug to deform if shot out of a choked barrel, they don't do much for stability.
I long for the day that Ireland gets its rightful revenge on the bongs
Yes, I could
Smooth bore Cannon relies on fin stabilization much like an arrow, dart or a airplane. Since a faster speed does not introduce yaw or precession, it is much more accurate at velocities above 3500fps. What your limitation becomes is the super to trans sonic shockwaves and plasma, that can alter trajectories. This is usually mitigated by the materials and design of the dart itself.
I nutated in you're mother last night.
Was it a Yaw, precession or nutation movement?
Ok, then what about artillery? Is it because they go subsonic during flight? Most modern artillery fusing uses radar or timing and isn't dependent on spin. Wouldn't higher velocity artillery mean greater range and more options for guidance and higher accuracy? So a 105 size shell, smooth bore, and maybe a slight rocket boost for speed and tail drag reduction as well as slight thrust and fin steering and target scanning much like bomblets in some antitank weapons do.. Anyone going these directions in artillery development?
A dart-shaped artillery shell would have terrible HE filler and fragmentation capacity.
If you can't make the artillery shell into a dart, you're limited by aerodynamics. Instead of trying to make the shell go faster, you try to retain speed (better BC, base bleed, rocket assist).
It would make it less accurate for unguided shells, which you do need to be able to do. As this war has shown, absolutely no one has enough guided artillery shells for 100% of fire missions.
>Smooth bore Cannon relies on fin stabilization much like an arrow, dart or a airplane. Since a faster speed does not introduce yaw or precession, it is much more accurate at velocities above 3500fps. What your limitation becomes is the super to trans sonic shockwaves and plasma, that can alter trajectories. This is usually mitigated by the materials and design of the dart itself.
Just to add to this anon, another combat reason is that tanks have a primarily anti-armor role. There is a maximum length/diameter ratio beyond which spin stabilization doesn't work anymore, but kinetic armor penetration increases with sectional density and velocity. Switching to a fin stabilized dart allows all that to be increased beyond what any spin stabilized round could offer, meaning the same caliber gun can pen much more armor vs needing a bigger, heavier gun.
HEAT warheads don't work as well out of a rifled barrel because the rotation tends to fling the liquified copper outward in a ring instead of directly forward into the enemy armor. Rifled barrels are also more expensive to make, and with aerodynamically stabilized projectiles they're pointless.
Yes and no. Post-WWII there were HEAT shells meant for rifled guns designed to counteract this effect. IIRC one of the earliest examples was the french OCC 105-F1. That's how you get 100-105mm HEAT shells in the 60's and 70's that make a mockery out of any realistic armor package before modern composites.
Pretty sure the earliest is T108/M348 for the 90mm guns that was finstabilized in the 1950s.
Fin stabilisation was done by having an obturator ring allowing the projectile to not engage with the rifling. Only the french went with their autistic ball-bearing method.
But yeah, firing fin stabilised ammunition out of a rifle barreled has not been a problem since the 1950s.
Rifling makes a bullet spin, this increases accuracy. There is also a trade-off, it reduces velocity. In the case of a tank, people would rather have the extra armor piercing capability which comes with added velocity. A rifled tank cannon would be more accurate than a smoothbore, but it's kinda pointless because a smoothbore cannon is already accurate enough, and it delivers higher velocity.
As others have pointed out, spin is not the only way to stabilize a projectile, and APFSDS projectiles are stabilized just like an airgun pellet, foster slug for a shotgun, arrow, or a badminton shuttlecock: the center of mass lies in front of the center of drag so it always flies nose-first.
Wrong. Next
They’re innacurate and often times require 2 piece ammo. I don’t think there’s many tanks with rifled barrels around anymore. At least none of the major tanks
whether or not the ammo is unitized or is in 2 pieces has nothing whatsoever to do with the rifling (or lack thereof)
I’m not entirely sure you are correct.
You mean besides the fact that there are tanks in Ukraine with smooth bore barrels that use 1 piece ammunition fighting against tanks in Ukraine with smooth bore barrels that use 2 piece ammunition?
What shitboxes in Ukraine use 2 piece ammo?
>he doesnt know
That piece of shit Britain gave to them
Wait the british don’t use single piece ammo?
not since chieftain introduced 2-piece ammo with its 120 mm gun...
Jesus Christ. I thought the British sucking at designing armored vehicles was just a meme
>designing armored vehicles
Anon, ALL bri'ish design is fucked. Just wait until you see how they designed their women's vag00s.
Ahh, a British ten.
South londons makeup styles is honestly horrific and makes them look uglier than they are. Thank fuck it's confined mostly to that area, with only a few slags elsewhere following the trend.
Two piece ammo isn't that much of a problem really. It is actually easier to handle shorter projectiles in a cramped fighting compartment than long unitary cartridges. A skilled loader gets about the same rate of fire IIRC.
British 2 peice ammo is a great design for them.
Compare their early ROF with their ready rack vs other nations.
round the 30 second mark
T64 and derivatives use 2 piece ammo. T62 uses 1 piece ammo. Both are smoothbores.
Alternatively, what’s the reasoning behind 2 piece ammo
space
space, weight.
With older tanks with smaller guns 1-pc ammo was practical but as tank rounds get larger and larger 1-pc ammo becomes increasingly difficult to handle, complicates loading, etc.
Smaller turret, smaller autoloader, smaller tank, lower weight.
With 1 piece ammo you need a stable shell casing - just like a comedy sized bullet - And have to deal with the weight of that brass, and have a plan of what to do with the case after its fired meaning you either need to stow the shell case or have it loose inside the tank, both slow RoF
With 2 part ammo you have a bullet and the charge is in a combustable bag - this means that
1. theres no wasted weight in brass
2. The 2 parts can be individually crammed in more places allowing more ammo in total
3. no dealing with clearing the breech after firing - bullet is gone, bag burnt up
4. IN THEORY more ammo versitility - You can take a number of charge bags, and the number of shells can be more than that mix and match as needed, also in theory you can under charge HE rounds to lob them like budget arty to clear cover
To look at the 120mm L11, you have to compare it to the 105mm L7 and the 120mm M58/L1 used on M103/Conqueror. The issue with the 120mm on the heavy tanks is that the brass case propellant was massive (nearly 900mm long) and heavy making it a bitch to handle.
The goal of the L11 was to have equal or better anti-armor performance to the M58/L1 whilst having not having such a big drop off in ergonomics (reload and ammunition count) compared to the L7 and this was achieved by making a combustible cased cartridge
1. Space efficiency
Instead of a 1m long projectile, you have two ~500-600mm projectile + propellent.
Length is more of a limiting factor then width, hence why every tank with the NATO 120mm armed tank have around ~40 rounds of ammunition, while Challenger 2 has 50 rounds
And how Chieftain had something like 54 rounds of 120mm while M60, Leopard 1 had around 60-65 of 105mm and Conqueror could only hold 35 rounds.
The smaller length of the individual sections also meant it was easier to handle inside the tank
Compare this
?t=1271
to this https://www.youtube.com/watch?v=e6hh-CoPKqU
2. Weight
L11 did away with brass cases, which reduces the weight of the propellant a lot. This makes it easier for the loader to handle the ammunition. It also enables lap loading where the loader can hold the light and inert APDS projectile in preparation to shove it in after the gun has fired, saving time.
And two other improvements to the case combustible charge were
A) less smoke in the fighting compartment from the smoldering brass cases
B) Many video games (even sims) don't model this, but the brass tray on the floor of a tank (if it even has one) usually only holds around ~5 fired rounds. After that the brass overflows and rolls on the turret floor until it is thrown out by the loader through the hatch. Not ideal. The 120mm L11 doesn't have this problem
Dude shut the fuck up. Rifled barrels are absolute garbage
Which is why the newest US tank has... a rifled barrel
nah it's cuz the US still has a lot of 105 ammo. it's the same reason why they wanted to use the striker mgs
even today soviet smoothbores use two-piece munitions, while the indians designed a unitary 120mm shell for their rifled arjun (THIS IS NOT ENDORSEMENT)
what kind of propellant do they use?
>I’m not entirely sure you are correct.
Explain why rifling would have any effect on case design then. There's no logical reason why one would have any effect on the other.
>but can you provide a source for that claim
I'm an engineer, and I can't think of a logical connection between the two. In fact, the implication that rifling has anything to do with the case design strikes me as absurd, like someone claiming that blue-painted cars must have manual transmissions, or some similar nonsense scenario where there's no rhyme or reason why the two things are associated together.
>blue-painted cars must have manual transmissions
That's obviously absurd because everybody knows it's the red cars that have to have a manual transmission.
Not that I don’t believe you but can you provide a source for that claim
Brit tanks vs soviet T series shitboxes
Both 2 part ammo, 1 rifled 1 not.
there are dozens of tanks that used rifled guns with unitary ammo...
No sorry
Guns fire lead bullets that need to spin, tanks fire big metal nails that don't need spin just go straight and fast as possible
If you were firing loads that made Bubba's pissing hot loads look like squibs, propelling a precision machined sabot that carries a precision machined lawndart, you'd also be wanting a smoothbore over a rifled barrel.
I just want to get something straight, is a rifles gun on a tank considered a flaw?
nowadays, yes
Thank you I’ve just decided on a new series of threads
Generally yes, but if you use a lot of HESH or HE(like the British), rifled barrels can still be useful.
>armor evolved to defeat HEAT
>high velocity and sectional density became the best way to pen armor
>looooooong bullets can't be stabilized by spinning
>therefore use fins
>therefore smooth barrel
>Tfw either HEAT is going to come back due to all the anti dart armour
Or
>The existance of HEAT keeps the armour against APFSDS less effective because it has to be able to handle two things
Rifled my beloved
On this point, HEAT shells were actually a motivator in moving away from rifled bores as well.
The high speed rotation of a spin stabilized projectile disperses the Munroe jet and makes it less effective.
Rifles shoot bullet.
Tank guns shoot arrows.
Sabot
Fins don't need and probably better off without gyro stability. And rotation disturbs HEAT jets, too.
A lot of emphasis is made on tank to tank combat than min drag max payload.
Wear, cost and energy efficiency. Besides that, a very dense and fin stabilized dart at 1800m/s has almost no spread, so the rifling is unnecessary.
>bad
Because aspect ratio of projectile dictates the twist rate on the gun needed to stabilize.
Modern AP is very high aspect ratio, which would need a very high twist rate to stabilize
Very high twist rates cause lots of friction and limit muzzle velocities.
Rifling is also prone to wear, with modern smooth bore guns actually having pretty good service lives.
It's not a bad thing really for a tank as it's far more accurate, especially at range, than a smoothbore gun. Smoothbores have their own advantages as well but it's not simply a matter of one is outright better.
tanks are big enough to carry armor that can unspin the bullet, stopping it completely.
Rifling in tank good, unless using fin-stabilised ammunition
Rifling throws off fin spin and thus fucks accuracy
It comes down to Sabot rounds. Namely they don't work in rifled barrels. The brits cheated by adding ball bearings in the shoe but it was still a bad solution.
>Namely they don't work in rifled barrels.
This is just wrong
105mm L7/M68 had more fin stabilized rounds developed for it then spin stabilized
You mean the Royal Ordinance L7? Yeah, they used ball bearings but it added weight to the sabot and reduced accuracy.
You don't know what you are talking about.
OCC 105 F1 used ball bearings so the HEAT warhead doesn't spin
Other 105mm HEAT-FS and APFSDS ammunition used an obturation ring so the projectile didn't engage with the rifling
There is actually nothing wrong with spin stabilised accuracy wise.
The problems from rifling comes from two things
Lower barrel pressures due to difficult to mate shells to barrels, causing drops in pressure, and loss of speed from friction with the barrel, meaning the shells dont get that extra oomph a well mated smoothbore gets.
Harder to manufacture barrels with high accuracy and an accurate curve using the lasers rheinmetal use on their smoothbores, so they smoothbores are also cheaper to manufacture
HEAT rounds or long-rod penetrators are negatively affected by spin generally, as they fuck with the formation of the copper, and the rods ability to penetrate.
Funnily enough, large calibres like artillery only firing generic dumb HE actually dont mind these issues, since the larger diameter means the slippage is more minimalised, and they actually benefit from the spin accuracy wise on dumb shells, and they dont need to penetrate anything really.
Sure, a smoothbore might get more range, but the lack of a spin would fuck with a generic HE rounds accuracy since they're not always perfectly formed, so we mostly just use rifles barrels instead.
Anime expert here, a tank is not a rifle.
I never thought I would say this but every time someone mentions the Challenger they somehow lose all their iq and restore to being eleven year olds in mentality.
The Brits use a rifled barrel for HESH ammunition which doesn’t give two shits about speed, pressure or penetration because it turns the enemy armor into a weapon itself. Being hit by HESH is like someone setting off a claymore in the tank and is more than good enough to destroy any modern tank by reducing the crew to the consistency of tomato paste. It needs a rifled barrel to apply the spin which distributes the plastic explosive better before detonation.
Also everyone here is obviously a slanty eyed yellow turbo garden gnome.