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enigma
06-25-2007, 04:01 PM
I thought some of this information would be useful for you all…

The calibre of the British guns which used the term “Pounder” and some additional information regarding them.

One should note that the weight the guns are referring to is the cartridge, not the shell like I had once thought or as I’ve seen others suggest because they pounded the enemy or the most bizarre one the price of production per unit!


AT Guns


2 Pounder QF – 40mmL52

It was the British standard Anti Tank gun of the years leading up to the war and the early years of the war. The 2 Pounder was lethal in comparison to other AT guns of similar calibre and iirc at under certain ranges could out perform the German Pak38 50mm gun.

The gun, or at least some sort of modification of it was used in the early British tanks. These included the Cruisers (including the Crusaders) and the early Infantry Tanks (Matilda, Valentines and iirc the first batch of Churchill tanks).

The gun fails when compared to the long barrelled 50mm gun used by the up gunned Panzer IIIs (known as Panzer III Specials to us Brits) or the short 75mm gun as used by most MK IVs during the early to mid war years.

In comparison to the Italian tanks, this gun could eat through them no problem.


6 Pounder QF – 57mmL43 and 57mmL50

This gun had been designed basically on the outbreak of war and was ready for production by the time German attack against the West began.
However due to the loss of so much equipment at Dunkirk, the 2 Pounder was kept on the production line so not to halt production of AT guns while the factories switched over to making the 6 Pounder.

When this gun did enter service during the middle of the war (around 1942 iirc), the 2 Pounders where turned over to the infantry when the AT batteries received there new guns.

Again this gun was an absolute lethal killing machine in comparison to other AT guns, ive got no charts in front of me but I would not be surprised if the only gun to out perform the 6 Pounder in killing power would be the long barrelled 75mm gun and the 88.

The gun was also used in several of the mid war tank even though the American M3 and M4s were becoming more and more common.
Examples would be the Valentine Tanks, some versions of the Churchill, the Crusader III and the early variants of the Cromwell (Centaur etc).

17 Pounder QF – 76mm (or 76.2mm to be really anal about it)

This is the more famous of the British AT guns and probably the only one most people will know the actual size without having to go and look it up! :)

This was brought into service from ’43 onwards. I don’t have much information on the gun as I have been able to provide for the others.

What I can tell you is what you probably already know, a chopped up version of the gun was used in the Sherman tanks which were nicknamed “Firefly’s”.

Iirc it was a new version of the 17 Pounded QF, which they designed to be used in tanks. I also recall mention of the gun had to be turned on it side to fit in the turret of the Sherman.
With the Sherman they had to chop out the back of the turret and plonk on a massive box, which was where the gun recoiled into.

Several other tanks used versions of the 17 Pounder, there was the Challenger, a Cromwell tank chassis with a massive superstructure on it which the gun sat in.
We also had the Archer, which was a tank destroyer and sported the gun. It was built on Valentine chassis and had the gun facing to the rear and could not be rotated (ala the Stug).
The idea being that it would reverse into an ambush position, fire one or two rounds and would be able to dart on out of there faster then a more conventional tank or TD could do by reversing.


Arty


18 Pounder QF - 84mmL29

This was the British Army’s main artillery gun during the First World War coming into service during the early years of the century; it remained in service until 1942 when the last units were retired from service (although I’ve read that they had already been moth balled during the inter war years when the 25 Pounders started coming onto the scene).

It served in the North African and East African theatres during WW2 along side the new 25 Pounders but am not sure if it was used with the B.E.F. in France or elsewhere.

Some of the latter marks of the gun were converted into 25 Pounders by re-boring the barrels.

25 Pounder QF – 88mmL31 (87.something or other to be really anal again :p)

This was the workhorse of the Royal Artillery during World War Two and was brought into service pre war to replace the older 18 Pounder’s.

It was that well liked that it remained in service for years after the war until iirc it was retired from service due to it not being combatable with new NATO rounds (which the troops didn’t like one bit).

It would appear that our forces did have anything in comparison to the German or American 105mm guns. The next jump in arty size goes into the howitzers, which are measured in Inches whom were used by the Medium and Heavy Regiments.

In general it was the Field Regiments, which were armed with the 18 and/or 25 Pounders.

sid
06-25-2007, 04:30 PM
Thanks mate nice info, you might want to delete the other two threads though.

Manstein
06-25-2007, 04:32 PM
that's good info to have, I was under the impression that 25 pounders were at least 105mm

Josh_HLB
06-25-2007, 04:58 PM
Some Penetration tables for those guns



6 pdr

APDS shell

Armour-30 degrees- 130mm@500m 110mm@1000m 100mm@1500m 90mm@2000m

APCBC shell

Armour-30 degrees- 85mm@500m 74mm@1000m 66mm@1500m 53mm@2000m


17 pdr

APCBC shell

Armour Penetration

0 degrees- 172mm@500m 162mm@1000m 150mm@1500m
30 degrees- 140mm@500m 120mm@1000m 112mm@1500m 100mm@2000m
60 degrees- 62mm@500m 58mm@1000m 55mm@1500m

APDS shell

Armour Penetration

0 degrees- 248mm@500m 231mm@1000m 213mm@1500m
30 degrees- 208mm@500m 192mm@1000m 172mm@1500m 145mm@2000m
60 degrees- 70mm@500m 65mm@1000m 60mm@1500m

enigma
06-25-2007, 05:55 PM
Cheers for the additional info! :)

Yea didnt realise 2 new threads popped up with this one ... meh i keep having problems with the forums lol

sid
06-25-2007, 06:08 PM
Me too, half the pages don't load properly or just don't load at all.

Josh_HLB
06-25-2007, 11:52 PM
Forgot the 2 pdr and added 20pdr, although i don't think it was used in WWII very much..




2 pdr

All Armour Penetrations at 30 degrees

AP shell- 57mm@500m 40mm@1000m

APHV shell- 66mm@500m 45mm@1000m

APCBC shell- 57mm@500m 50mm@1000m 40mm@1500m

APCNR shell- 88mm@500m 57-72mm@1000m


20 pdr

APDS Mk I shell

0 degrees- 300mm@500m 280mm@1000m 260mm@1500m
30 degrees- 240mm@500m 225mm@1000m 210mm@1500m
60 degrees- 80mm@500m 75mm@1000m 67mm@1500m

-X-Sublime
06-26-2007, 01:18 PM
what kind of armor rolledsteel or just plane sheet

BillSpargo
06-26-2007, 04:02 PM
Quick quiz: What does the "L" followed by a number mean?

Manstein
06-26-2007, 04:04 PM
it is known as the "caliber" of large bore cannons

it's the length of the barrel in diameters of the bore

for example, the Tiger 1 had an 88mm L/56 cannon, meaning the barrel was 4928 mm's long, or 4.928 meters

enigma
06-26-2007, 05:01 PM
It would appear to work out the length of the gun then ...


To convert from calibers to:

inches, multiply by 0.01.
millimeters, multiply by 0.254.

Iirc the longer the gun the faster the round goes.

BillSpargo
06-26-2007, 05:59 PM
it is known as the "caliber" of large bore cannons

it's the length of the barrel in diameters of the bore

for example, the Tiger 1 had an 88mm L/56 cannon, meaning the barrel was 4928 mm's long, or 4.928 meters
exactamundo:D

Josh_HLB
06-26-2007, 06:13 PM
what kind of armor rolledsteel or just plane sheet


I don't recall, they are from differnet places, but i think they are mostly sheets. But im not sure.

enigma
06-26-2007, 06:45 PM
Whats the differance?

Manstein
06-26-2007, 07:07 PM
Iirc the longer the gun the faster the round goes.

To a point it will, that's why the Germans switched from the L/42 to the L/60 50mm cannons, and from the L/24 to L/43 to L/48 to L/70 75mm cannons

BillSpargo
06-27-2007, 06:11 AM
Once the gases stop expanding at a rate and pressure greater than the round the round stops accelerating.
A practible barrel length where a tank can still operate in its environment and be balanced on the chassis is what designers would be looking at. The Sherman Vc Firefly needed counter-weights attached to the bussle of the turret to balance the larger gun. Otherwise there would have been uneven pressure on the turret ring leading to jamming and failure.

Also the Germans used homogeneous rolled steel (due to costs) while the US used faced hardened steel which was more effective at deflecting angled shots.

OliverMarshall
06-27-2007, 02:06 PM
The 17lbr is regarded by many as the best Allied AT gun of the war, inferior only to the German 88.

http://en.wikipedia.org/wiki/17_pdr

[BEF]-R!G4M0RT!Z
06-27-2007, 02:18 PM
Thats because its British ;)

enigma
06-27-2007, 04:29 PM
Once the gases stop expanding at a rate and pressure greater than the round the round stops accelerating.
A practible barrel length where a tank can still operate in its environment and be balanced on the chassis is what designers would be looking at. The Sherman Vc Firefly needed counter-weights attached to the bussle of the turret to balance the larger gun. Otherwise there would have been uneven pressure on the turret ring leading to jamming and failure.

Also the Germans used homogeneous rolled steel (due to costs) while the US used faced hardened steel which was more effective at deflecting angled shots.

I was under the impression the overhang was mainly for the recoil of the 17 pounder ... otherwise if it wasnt there, there would be an odd shaped gun impression on the back of a regular sherman turret :p

Btw it would appear that the 17 Pounder with APDS (tungsten?) rounds does indeed beat the German 88L71 AT gun.

Manstein
06-27-2007, 07:45 PM
the overhang serves both purposes

and the 17 pounder doesn't outshoot the 88mm L/71 according to this source
http://www.panzerworld.net/armourpenetration

17 pounder at 30 degrees:
APCBC: 140mm@500m 120mm@1000m 112mm@1500m 100mm@2000m
APDS: 208mm@500m 192mm@1000m 172mm@1500m 145mm@2000m

88mm L/71 at 30 degrees:
APCBC: 185mm@500m 165mm@1000m 148mm@1500m 132mm@2000m
APCR: 217mm@500m 193mm@1000m 171mm@1500m 153mm@2000m

they are almost identical in performance when shooting the best shells, and normal APCBC is clearly in favor of the 88mm L/71

still, though, that 17 pounder was a terror

enigma
06-27-2007, 08:15 PM
Thing is, would have the Germans access to Tungsten since iirc they ran out of there stocks for it mid war.

But alas it seems i may have been mis informed regarding the penetration power of the 17 pounder.

Josh_HLB
06-27-2007, 08:51 PM
Either way, the 17pdr could knock out a Tiger I by hitting it in the front. The tigers armour was 100mm at less than 30 degrees in the front, with the exception of the part below the Hull MG. But its barley visable when looked at head on. So weither it outperformed the 88 L/71 or not, it was a amazing gun.