Smoothbore or rifled?

I always figured that rifled are better because it imparcts higher velocity and achieve better accurarcy.

I guess the smoothbore is more versatile can fire a more variety of rounds, including the missile rounds. That is why most modern MBTs, such as the Abram, the Leopard, and the Russian T-72 carry the smoothbore. The British Challenger and the Indian Arjunmk are really one of the few modern MBT that still carries the rifled gun, as it is needed to fire the unique HESH rounds.

 

Do you know why HESH has to be fired from a rifled gun? The British used HESH as a duel purpose round because HEAT is degraded by spinning and the APDS was a killer. Before APDSFS if you wanted a kenetic energy round it had to be APDS so that meant rifled guns. Most Western nations used or made the British 105mm which was rifled.

The Soviets had long range problems with their 125mm smoothbore that they had to part-rifle it just to impart a bit more spin. Did read they even drilled diagonal holes in the base of the shells to impart some spin from their smoothbores but not sure if this was true.

 

I read about a modern HEAT shell (I think it was German) where the warhead is mounted on ballbearings, so that it spins slower than the shell itself, and is therefore more effective.

 

wow! complicated.

 

I've heard of that kind of thing with missiles didn't realise it extended to shells. Explanes though why the ammo is so expensive. I wonder is the next generation of tanks going to include a system to compare value of target to cost of the ammo before it lets you fire?

 

If the Treasury have their way...

 

The HEAT warhead on ball-bearings was used by the French in the 105mm on the AMX-30. Took sometime to get right but not sure if it was used or copied by anyone else.

 

Ironically, during the Crimean war the British and their Allies had an advantage over the Russians because they had rifled barrels instead of smoothbore ones. Back then rifling meant a considerable increase in range.

 

An early vivid demonstration of the effectiveness of rifled cannons can be found in Fort Pulaski near Savannah, Georgia. In 1862 during the American Civil War the Union army laid siege to the fort. From distances of nearly 2 miles out, they used heavy caliber rifled cannons and shaped projectiles (instead of cannonballs) to reduced the previous inpenetrable fortress wall, forcing its forces to surrender. The holes and caved in sections of the battered wall is still evident 142 years later. I was fortunate enough to visit the fort/museum 2 years ago. The historical and charming city of Savannah is only 30-45 minutes driving distance.

 

It should be mentioned that Fort Pulaski is a masonry fort.

 

I don't know what those fort builders thought, but i think building something that is supposed to withstand immense impact out of bricks is pretty stupid. Any reason for that work of genius?

Price I guess?

 

Until the appearance of the large caliber high velocity rifled cannons and later on high-explosive shells, most masonary forts with its thick walls could hold out against bombardment from smooth bore artilleries. Of course that was quickly changed to reinforced concrete soon after.

 

:lol:

 

Rifling doesn't necessarily mean more RANGE, it means better shot stability and therefore better ACCURACY to a given range.
Smoothbore will given a higher muzzle velocity (less friction is the barrel because the driving bands don't have to engage the rifling), Simpkin (see one of my other posts on him) reckoned that a smoothbore gave the equivalent of 10mm of calibre advantage over a similar calibre rifled weapon.
Oli

 

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the brick forts were designed to fight ships not land based guns and they were built before rifleing was common. the odds of a ships guns ever hitting in the same place twice were remote at best and the brick stood up to the impact of a ball fairly well. against land mounted rifleed guns they stood no chance.

the MAIN reason for smoothbore tank guns is the long rod penerator. rifleing can not stablize a long rod so it must have fins. the 105 rifled gun in the early M-1s used a sabot with a slip ring to get around the spin from the rifleing.

a squish head round spreads out against the struck surface better if it is spinning but they will work with smoothbore guns also. spin will degrade a heat round's penetration

smoothbores do last longer due to less barrel erosion.

to my knowledge nobody has come up with a really useful gun fired anti tank missile yet. for one the diameter is too small to get a good HEAT charge in it. all HEAT warheads need more room then you can get in a gun.

 

Re: items

Squash head is used only by the UK AFAIK, and we've always fired it from rifled guns.
Smoothbores don't necessarily last longer, designers tend to think in terms of "if there's less internal friction we can bump up the propellant charge and REALLY get something out of this". Barrel EFC (Equivalent Full Charge - effective life/ no of shots) is roughly the same, it's material science advances that increase barrel life.
Gun diameter too small???? :lol: With most guns around 120-125mm how big do you want a hollow charge warhead? Trigat MR is 100mm, Milan 116, Sagger 120, Gill/Spike 126. Dragon 127,TOW 127, the latest American ATGW, Javelin is 126mm. Yeah, the larger-non-portable ATGMs are around 150-160mm, but bear in mind that different liner materials, better cone shaping and improved stand-off for jet formation can increase the increase the penetration from WWII's 3-5 diameters up to 8 or 10.
RPG-7 is 88mm, LAW is 66mm, as was bazooka ....
The reason for ATGW fire from tank guns is that, roughly speaking, tank gun hit chances decrease with range, and ATGW hit chances increase with range. ATGWs are meant to be used to about 4000m, guns at 2-25000.
Oli

 

lots of HESH users

almost all recoiless guns had a HESH round. true they tend to be rifled but its not because of the HESH. HESH works just fine from a smoothbore.

given equal loadings smooth bores will last longer

 

Nope, most recoilless used HEAT, not HESH (or HEP as the yanks called it).
Agreed equal loadings.
Oli

 

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And India, who also use rifled guns.

 

Wasn't aware of India, was that because they got it as a standard round with Centurion?
Oli