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Posted: Tue Apr 10, 2012 12:42 am
by jackssmirkingrevenge
wyz2285 wrote:But fire arms were very available already in the early 20th century...
Apparently the reason they went for the pneumatic mortars is that they were much more quiet than powder burners and also flashless, making them less easy to pinpoint for counter-battery fire.

These days there are much more compact solutions if stealth is required, the Fly-K mortar is a good example.
Well some FX airguns are only rifled in the end of the barrel, giving the pellet a initial space to accelerate, then in the end, give it the spin.
Interesting, not really a new idea though. You can get rifled chokes for shotguns, and the Paradox gun class have used limited rifling at the muzzle since the 19th century. I'm also interested in the type of rifling, from the video it seems to suggest that it's a Whitworth type as opposed to lands and grooves.

Good article here:
you think you invented something and then you find out that the thing had been created years ago


That happened with the "rattlesnake" valve which I found out had been patented in 1928... ah well, nothing new under the sun :)

Posted: Tue Apr 10, 2012 7:33 am
by POLAND_SPUD
that happened with the "rattlesnake" valve which I found out had been patented in 1928... ah well, nothing new under the sun
It reminds me of the bo-at[youtube][/youtube]ohh btw I actually think you are like Doofenshmirtz...
because of you know... a lab coat and failures
I'm also interested in the type of rifling, from the video it seems to suggest that it's a Whitworth type as opposed to lands and grooves.
No way... you can't use APFSDS ammo with a rifled barrel... :-D

plus I don't think it is worth it... for larger projectiles fin stabilised or drag stabilization seems to make more sense... there is a reason why most mortars use fins

Posted: Tue Apr 10, 2012 11:07 am
by Hotwired
Anyone else taking note of the Luftminenwerfer using one tube and no chamber (as such)?

Requires fair bit of work for each projectile when you have them participating in the mechanism but since shells have to be manufactured anyway I doubt it was much of a problem.

I still say a hollow projectile > a spindle if the projectile is the length of the barrel.

But with the barrel much longer, a spindle looks more attractive.

Posted: Tue Apr 10, 2012 11:12 am
by Hotwired
POLAND_SPUD wrote:
I'm also interested in the type of rifling, from the video it seems to suggest that it's a Whitworth type as opposed to lands and grooves.
No way... you can't use APFSDS ammo with a rifled barrel... :-D
The challenger 2 has a rifled barrel and does exactly that.

Uses bearings to minimise spin on the projectile.

Posted: Tue Apr 10, 2012 12:57 pm
by POLAND_SPUD
The challenger 2 has a rifled barrel and does exactly that
ohh yeah that's a practical solution :D
Dude who needs rifling?? tanks with smoothbore barrels are doing fine

Posted: Tue Apr 10, 2012 1:23 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:I actually think you are like Doofenshmirtz...
because of you know... a lab coat and failures
Cheers :)

I love the way that in Spanish he's Perry el Ornitorrinco :D
plus I don't think it is worth it... for larger projectiles fin stabilised or drag stabilization seems to make more sense...
I see some situations where rifled projectiles can be beneficial, certainly if I had easier access to rifled barrels I would use them.
Dude who needs rifling?? tanks with smoothbore barrels are doing fine
The primary reason the Brits clung to rifled barrels longer than anyone else is their love of High Explosive Squash Head rounds, however most modern tanks incorporate spaced armour which effectively nullifies most of the effects of these rounds making them much less relevant on the battlefield.

Certainly there seem to be no complaints about the accuracy of fin stabilised HEAT rounds from smoothbore barrels, and indeed the M830 round is also subcalibre, giving the benefits of lower sectional density and higher muzzle velocity giving a flatter trajectory. The effectiveness of shaped charges is however proportional to diameter so this is also a compromise.

Image
I still say a hollow projectile > a spindle if the projectile is the length of the barrel.


The 10.5cm mortar mentionedhere actually uses a fin stabilised round.

Posted: Wed Apr 11, 2012 7:47 am
by Hotwired
jackssmirkingrevenge wrote:The primary reason the Brits clung to rifled barrels longer than anyone else is their love of High Explosive Squash Head rounds, however most modern tanks incorporate spaced armour which effectively nullifies most of the effects of these rounds making them much less relevant on the battlefield.
That they do but HESH was created as a bunker buster which was then realised to have good effect vs single layer armour.

It's still a bunker buster but smoothbore is better for long rod penetrators and HEAT and lousy for HESH.

So a compromise in favour of anti-fortification or anti-MBT.

Or another way of looking at it, keep a British weapon or dump it.
jackssmirkingrevenge wrote:
I still say a hollow projectile > a spindle if the projectile is the length of the barrel.


The 10.5cm mortar mentionedhere actually uses a fin stabilised round.
It's not the length of the barrel, if it was it would only travel a short distance before exhausting all trapped gases behind it.

If it was the length of the barrel it would require a hollow projectile to trap the gas behind it until it had travelled the full length of the barrel.

Posted: Wed Apr 11, 2012 12:41 pm
by jackssmirkingrevenge
Hotwired wrote:It's still a bunker buster but smoothbore is better for long rod penetrators and HEAT and lousy for HESH.
If it works for HEAT I don't see why it would not work for HESH, it would still be a fin stabilised projectile of similar external shape.

So a compromise in favour of anti-fortification or anti-MBT.
It's not the length of the barrel, if it was it would only travel a short distance before exhausting all trapped gases behind it.

If it was the length of the barrel it would require a hollow projectile to trap the gas behind it until it had travelled the full length of the barrel.
True, I'm reminded of this in the French mortar thread :)

Image

Re: Austro-Hungarian valveless pneumatic mortars of World Wa

Posted: Sat Oct 15, 2016 4:56 am
by Belcher
jackssmirkingrevenge wrote:I had touched on the subject of these devices here, and posted some details of French launchers of the same era here.

The Austro-Hungarian empire was heavily involved with such mortars, they are detailed on this fine (German language) page.

Having had the opportunity to look at surviving examples of the 12 cm Luftminenwerfer M.16 and 20 cm Luftminenwerfer System Bartlmus preserved at the Heeresgeschichtliches Museum close up, I thought I would share some photos. Not my best effort, flash photography was not allowed.

Unfortunately I was unable to get any details of the clutch, but the function can be easily imagined as a quick-release mechanism which releases the projectile when pulled.

One thing I don't understand is how the projectiles are stabilised. Having seen the studs on the projectiles, my initial idea was that they engaged rifling in the barrel in a manner similar to the La Hitte system, but in actual fact the barrels are smoothbores, and the studs do not project beyond the major diameter of the projectiles.

Looking at a cross section, the CG and CP are about central, so it doesn't appear that it would be drag stabilised.

List of Unknown Facts of World War II

The most plausible answer to me is that the place where the projectile sits actually contains a short rifled section. Even thought it's only over half the length of the projectile, this could provide enough spin to stabilise the relatively short projectile in flight. The 20cm model had its breech open but a projectile was in place and I was unable to confirm this. Any other theories welcome :)

One other interesting thing is that the 12cm model has a spring loaded shutter at the muzzle. The springs look fairly weak so I imagine this was mostly to keep debris out when not in use, but it could also have had a limited suppressing effect.

I digress, herewith the pictures:
Can i see the image of 12cm model? I am a big fan of armors and keep looking for historic pieces.

Re: Austro-Hungarian valveless pneumatic mortars of World War I

Posted: Sat Jul 02, 2022 6:12 pm
by jackssmirkingrevenge