Tell Techno.

Started by Techno, 22 August 2018, 01:30:39 PM

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Raider4

The British 15" naval gun barrel is 52 feet long, but is still only 42 calibres.
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Westmarcher

04 August 2021, 09:29:37 AM #331 Last Edit: 04 August 2021, 09:38:58 AM by Westmarcher
Quote from: Lord Kermit of Birkenhead on 04 August 2021, 08:01:52 AM
Gota give you a headachce - no it would be 0.5"L22.5

No, Ian. L90. There are 90 half-inches in a 45 inch length.

[and to confuse everyone further, the Challenger 2 MBT is currently fitted with the L30A1 rifled tank gun but the "L30" has nothing to do with the length which is in fact, 55 calibres long (L55)!]
I may not have gone where I intended to go, but I think I have ended up where I needed to be.

Lord Kermit of Birkenhead

I only teach maths occasionally. The L30 is the model of the 120, we use L like the Yanks use M, ish
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Lord Kermit of Birkenhead
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steve_holmes_11

Now we know what (nn)L(nn) means, can somebody explain why it is used.

We usually adopt classifications that convey something important, or failing that a technical issue.
So who 15"L40 as opposed to 15"L50'.

Is there some "golden ratio" between gun calibre and length (Clearly would vary with role and construction).




Westmarcher

Quote from: steve_holmes_11 on 04 August 2021, 10:29:41 AM
Now we know what (nn)L(nn) means, can somebody explain why it is used.

We usually adopt classifications that convey something important, or failing that a technical issue.
So who 15"L40 as opposed to 15"L50'.

Is there some "golden ratio" between gun calibre and length (Clearly would vary with role and construction).

I assume it is simply to inform how long the barrel is. As Ian stated, we Brits use 'L" as part of our weapon model designation and has nothing to do with barrel length. As Ian also stated, longer barrel usually confers increased velocity and so longer range. No doubt there is some "golden ratio" for every type of gun which would depend on the role you want to use it for (e.g., short barrels for howitzers or combat in confined spaces, long barrels for long range shooting and/or greater armour penetration)

Here's a link to the Rheinmetall 120mm tank gun which was originally produced as an L44 and later upgraded by lengthening it to L55 which may help provide further info (or not).   :-[

https://en.wikipedia.org/wiki/Rheinmetall_Rh-120
I may not have gone where I intended to go, but I think I have ended up where I needed to be.

Lord Kermit of Birkenhead

The golden ratio seems to be L55-60 which most modern high velocity guns use. For artillery it can make sense to use shorter lengths to allow for lower minimum ranges to fire close in, but the trend seems to be for longer guns there. As for too long, in WWII our longest A/T gun was the 17pdr at L60, and like I said before the German 75/L70 and 88mm/L71 seem to lose accuracy due to barrel whip as they weren't sufficently rigid to take the firing stresses.
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Techno II

I've totally switched off, now. (:|

Cheers - Phil. ;)
I really shouldn't press buttons...before I know what will happen.<br />Probably STILL the most picked on member of the forum since the year dot.

Raider4

Quote from: Techno II on 04 August 2021, 05:34:11 PM
I've totally switched off, now. (:|

You can hardly complain when the friendly, helpful bunch that inhabit this place all rush to answer your question.
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Orcs

Quote from: Raider4 on 04 August 2021, 06:04:39 PM
You can hardly complain when the friendly, helpful bunch that inhabit this place all rush to answer your question.

I Know. I don't know whys he asks !.  He knows he will get 25 different answers:-
2 will actually be on the subject, but not answer the question
5 will be almost about the same subject but will raise other issues
The other 18 will cover subjects varying from the length of a Mittani skirt, the composition of the bronze in a 16th Century Ottoman cannon. and If Nik Harwood has replied "The hottest Redhead Totty on the planet".
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Scorpio_Rocks

Quote from: Westmarcher on 03 August 2021, 09:59:44 AM
p.s. The length of the barrel is usually measured from muzzle to breech. I'm not sure what the measurement parameters are for muzzle loading cannon (i.e., is it the length of the external tube or simply measured from the muzzle to the internal end of the tube?).

The "length" of the gun (the measurement given in calibres) is actually the length of the bore - so internally muzzle to inside of breach, doesnt include all breach, muzzle brake, etc.
"Gentlemen, when the enemy is committed to a mistake - we must not interrupt him too soon."
Horatio Nelson.

John Cook

Quote from: Techno II on 04 August 2021, 05:34:11 PM
I've totally switched off, now. (:|
Cheers - Phil. ;)

I do empathise, really I do ;)  I'll try to keep it simple :D

I don't know when it became the convention to measure the length of artillery gun barrels in numbers of calibres, but it seems to have started in the late 19th Century with breach loading naval artillery.  The lexicon of artillery can be quite mysterious but these are the terms you need in the context of barrel length. 

Bore = the internal space inside a barrel
Calibre = the diameter of the bore
Barrel = the tube from breach face to muzzle

For example, take the German 50mm anti-tank gun described as 5cm L/60.

Calibre: 5cm
Barrel length: 60 calibres
Therefore barrel length in cm = 5 x 60 = 300cm

Measuring barrel length like this, is not, in my experience applied to small or light arms. 

Ammunition is a different subject altogether.

Techno II

John. :)

Bless you for trying to explain (genuinely)...I thank you !

My head is going to genuinely explode, if I even attempt to follow this. X_X

Cheers - Phil.


I really shouldn't press buttons...before I know what will happen.<br />Probably STILL the most picked on member of the forum since the year dot.

Techno II

This one's a lot easier.  :D

Where does the description 'broom handle' come from on a "broom handled Mauser."

Is it just the hand grip ? Which I grant could be considered to be roughly the shape of the very end of a broom handle... or is it something to do with the wooden  'stoclk'.
That doesn't look anything like a broom handle....it looks more like a mutant sawn-off cricket bat.

Are ALL Mausers 'broom handle' types ?

Cheers slightly puzzled of Wales. :-\
I really shouldn't press buttons...before I know what will happen.<br />Probably STILL the most picked on member of the forum since the year dot.

steve_holmes_11

Quote from: Techno II on 10 September 2021, 05:15:44 PM
This one's a lot easier.  :D

Where does the description 'broom handle' come from on a "broom handled Mauser."

Is it just the hand grip ? Which I grant could be considered to be roughly the shape of the very end of a broom handle... or is it something to do with the wooden  'stoclk'.
That doesn't look anything like a broom handle....it looks more like a mutant sawn-off cricket bat.

Are ALL Mausers 'broom handle' types ?

Cheers slightly puzzled of Wales. :-

(It's the handle/grip).

Paragraph 2 line 2  https://en.wikipedia.org/wiki/Mauser_C96

Lord Kermit of Birkenhead

That it is, the grip is supposed to resemble a brush handle
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