Somebody mentioned 18x12"?

Started by Borys, September 11, 2007, 12:26:15 AM

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Korpen

Quote from: Carthaginian on September 11, 2007, 05:29:59 PM
Man, I don't know if the WORLD has ever seen a 105mm that could fire 80 RPM!
That's, like, a round every .6 seconds.
Most semi-auto rifles can't do that unless they are in very skilled hands.
First i would like to point out that a 12cm automatic canon is a tiny bit too large to be hand-held, no matter how skilled hands. ;)

And then I give you: http://www.navweaps.com/Weapons/WNSweden_47-46_TAK120.htm
12cm, 80 RPM.
If you are looking for a 10cm with that kind of ROF there is always the French: http://www.navweaps.com/Weapons/WNFR_39-55_m1968.htm
Card-carrying member of the Battlecruiser Fan Club.

Borys

#31
Ahoj!
AFAIK current 5 inch or so ship mounted guns are often water cooled. They are automatic, and can fire 10-12 rounds per minute. They can fore at this rate for a minute or two, and then have to cool down. Of they fre at a lesser rate for a longer period. Water cooling allows them to fire for longer

SP land 6 inch or s howitzers with automatic feed have similar capability. Here the idea is to fire of half a dozen rounds and scoot. The theorietical ROF of c.8-10 per minute cannot be sustained for over a minute due to heat.

http://www.navweaps.com/Weapons/WNRussian_51-70_ak130.htm

I do not believe in 40 rpm - maybe the mechanism could take it, but I doubt if the barrels can. What they can do is fire bursts - 4 shells in 6 seconds - then wait for a dozen seconds or so - then fire again. They still will overheat, but after 2 or 3 minutes, not withing 20 seconds.
That's how I understood this stuff, so I could be wrong.

A thing to be noted about the guns Korpen mentioned - they have ready use magazines which they can fire off in 20-30 seconds at full theoretical ROF.
THAT keeps them from overheating :)

Just like with a machine gun - after how many minutes of continuous fire, with no barrel swaps, will a MaDuece fail?

So it is a yes and no answer.
Yes, 6 inch guns can fire at 10 rounds a minute (or more).
No, they cannot do it for very long - such a ROF is counted in tens of seconds.

Borys
NEDS - Not Enough Deck Space for all those guns and torpedos;
Bambi must DIE!

P3D

There are no fielded fully automatic self-propelled artillery systems. The Germans, US and Russia has prototypes.
The first purpose of a warship is to remain afloat. Anon.
Below 40 degrees, there is no law. Below 50 degrees, there is no God. sailor's maxim on weather in the Southern seas

Korpen

Quote from: P3D on September 12, 2007, 12:59:46 AM
There are no fielded fully automatic self-propelled artillery systems. The Germans, US and Russia has prototypes.
That is incorrect: Bandkanon 1C
Full automatic feed, 14 rounds in 45 seconds. http://en.wikipedia.org/wiki/Bandkanon_1

Then you got a bunch of guns such as the FH-77 were the gun is automatically loaded from a loading tray, allowing it to fire a three round burst in about 8-10 sec.
And this is guns that is more the 30 years old...
Card-carrying member of the Battlecruiser Fan Club.

Carthaginian

Korpen,

These guns illustrate my point.
They may have a THEORETICAL cyclic of 80 RPM, but this cannot be achieved due to ammunition feed problems. Something that big just cannot be fed fast enough... heck, it's rough to keep a standard M2 .50 caliber fed to a point you can achieve it's full cyclic rate. To do that, you have to join belts prior to beginning your test, and THEN have to have 2 or 3 guys watching the belt to make sure there are no kinks, snags, or bad joints in the belts. On top of THAT, you have to be aware that the M2 is a closed-bolt weapon, and that if you get things too hot, you'll start getting cook-off's and mis-feeds.
So 'ere's to you, Fuzzy-Wuzzy, at your 'ome in old Baghdad;
You're a pore benighted 'eathen but a first-class fightin' man;
We gives you your certificate, an' if you want it signed
We'll come an' 'ave a romp with you whenever you're inclined.

Korpen

Quote from: Carthaginian on September 12, 2007, 07:26:05 AM
Korpen,

These guns illustrate my point.
They may have a THEORETICAL cyclic of 80 RPM, but this cannot be achieved due to ammunition feed problems. Something that big just cannot be fed fast enough... heck, it's rough to keep a standard M2 .50 caliber fed to a point you can achieve it's full cyclic rate. To do that, you have to join belts prior to beginning your test, and THEN have to have 2 or 3 guys watching the belt to make sure there are no kinks, snags, or bad joints in the belts. On top of THAT, you have to be aware that the M2 is a closed-bolt weapon, and that if you get things too hot, you'll start getting cook-off's and mis-feeds.
That applies to ALL automatic weapons, so far I have never heard about any weapon whose cyclic rate of fire is the same as its practical rate of fire.

However as the AA version of the 12cm TAK had 48 ready round, and had not problem firing them in one volley, them main reason larger magazines were not used was that the naval gun was intended for very light crafts.
Sure no matter witch gun you use sooner or later you will risk overheating, but it is a very minor problem compared to keeping the gun fed. :)
Card-carrying member of the Battlecruiser Fan Club.

Carthaginian

Quote from: Korpen on September 12, 2007, 07:52:09 AM
That applies to ALL automatic weapons, so far I have never heard about any weapon whose cyclic rate of fire is the same as its practical rate of fire.

Well, I HAVE come pretty close on an FN SAW.
It took 4 belts and a really good loader, but we burned about 650 rounds in a minute, on a weapon that had a cyclic of 800 RPM.

Of course, that was a few weeks before we got new barrels for our SAWs... we showed that barrel to the inspectors. Sometimes you gotta get creative to get new equipment. :D
So 'ere's to you, Fuzzy-Wuzzy, at your 'ome in old Baghdad;
You're a pore benighted 'eathen but a first-class fightin' man;
We gives you your certificate, an' if you want it signed
We'll come an' 'ave a romp with you whenever you're inclined.

P3D

Reminds me some Hungarian AK clone (AMD) where the barrel was made of cheap material, and would erode fast on full auto...
The other Hungarian AK clone had no such problems IIRC.
The first purpose of a warship is to remain afloat. Anon.
Below 40 degrees, there is no law. Below 50 degrees, there is no God. sailor's maxim on weather in the Southern seas

Carthaginian

Well, those have problems 'new in box.'
This weapon's barrel was at least 5 years and 1200 rounds old, and was starting to get rust spots. We just wanted something new ans shiny, so we did what the owner's manual said not to do. ;)
So 'ere's to you, Fuzzy-Wuzzy, at your 'ome in old Baghdad;
You're a pore benighted 'eathen but a first-class fightin' man;
We gives you your certificate, an' if you want it signed
We'll come an' 'ave a romp with you whenever you're inclined.

swamphen

Quote from: Carthaginian on September 12, 2007, 03:56:49 PM
Well, those have problems 'new in box.'
This weapon's barrel was at least 5 years and 1200 rounds old, and was starting to get rust spots. We just wanted something new ans shiny, so we did what the owner's manual said not to do. ;)

I.E., ignored the 'don't try this at home kids' label?  :P


Meanwhile:
*looks at Swiss "Agincourt", parked in Anchorage harbour, other end of ocean from Brandenburg*
*sees fuse burning on Swiss ship's centre magazine*
*dives into Brandenburgian foxhole and prays*
:D


P3D

Quote from: Korpen on September 12, 2007, 01:23:09 AM
Quote from: P3D on September 12, 2007, 12:59:46 AM
There are no fielded fully automatic self-propelled artillery systems. The Germans, US and Russia has prototypes.
That is incorrect: Bandkanon 1C
Full automatic feed, 14 rounds in 45 seconds. http://en.wikipedia.org/wiki/Bandkanon_1

Then you got a bunch of guns such as the FH-77 were the gun is automatically loaded from a loading tray, allowing it to fire a three round burst in about 8-10 sec.
And this is guns that is more the 30 years old...

True. However, Bandkanon uses fixed ammo, and has very limited flexibility compared to 5-6 zone charges. It is rather an MRLS/Katyusha-like area saturation weapon than modern SP Artillery that can do MRSI.
FH-77 is using special ammunition to reach that ROF, with NATO bagged charges ROF  is lower, and its flexibility is also limited. The export variant FH-77B has slightly lower ROF, but still higher than hand-loaded contemporaries (3 rounds in 10 vs 15s).
The first purpose of a warship is to remain afloat. Anon.
Below 40 degrees, there is no law. Below 50 degrees, there is no God. sailor's maxim on weather in the Southern seas

Korpen

Quote from: P3D on September 15, 2007, 12:43:05 PM
Quote from: Korpen on September 12, 2007, 01:23:09 AM
Quote from: P3D on September 12, 2007, 12:59:46 AM
There are no fielded fully automatic self-propelled artillery systems. The Germans, US and Russia has prototypes.
That is incorrect: Bandkanon 1C
Full automatic feed, 14 rounds in 45 seconds. http://en.wikipedia.org/wiki/Bandkanon_1

Then you got a bunch of guns such as the FH-77 were the gun is automatically loaded from a loading tray, allowing it to fire a three round burst in about 8-10 sec.
And this is guns that is more the 30 years old...

True. However, Bandkanon uses fixed ammo, and has very limited flexibility compared to 5-6 zone charges. It is rather an MRLS/Katyusha-like area saturation weapon than modern SP Artillery that can do MRSI.
FH-77 is using special ammunition to reach that ROF, with NATO bagged charges ROF  is lower, and its flexibility is also limited. The export variant FH-77B has slightly lower ROF, but still higher than hand-loaded contemporaries (3 rounds in 10 vs 15s).
Bertil is in fact a quite different gun from Adam, as it got an ogival screw breech, rather then the sliding breach block in 77A.
I think it is wrong to call the ammunition to 77A "special", as the only special thing about it was that it was not a NATO standard case, and at the time there was no reason to take that into account.

BKan had its drawbacks, nobody is denying that, but it was excellent at the work it did.
It did sever in the 2nd & 6th fördelningskanonbattaljonerna (divisional artillery battalions) in northern Sweden, and it main work was interdiction against a (soviet) invader. For this work, it very high ROF, long range (~26km) and good accuracy counted for much more then its inflexibility. As a side note, It could do MRSI. :)

By its nature rocket artillery require a larger weight of munitions to engage a target then conventional artillery. This means that while it is always cost-efficient to engage with shells, with rockets that is not the case.
MRSI is not something magical, it simply a usage of the fact that the effect of barrage is cut in half in 15sec again personnel.
Rocket artillery have its use, but so does the superior accuracy, cost-efficiency and readiness of conventional guns.


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