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Does L15 Apds Have An Expiry Date?


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#41 Wiedzmin

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Posted 10 June 2017 - 1311 PM

YjMgAu4WIEw.jpg

after hit on photo mantlet was cracked, for repair you will need new mantlet, new gun cradle and 300 hours of work

 

i haven't seen any reports about 115mm APFSDS behind armour effect, but all wars near Israel have so much myths... 

 

btw, L15A2 was used in this test, and maybe i will get something about L23A1, but not L23


Edited by Wiedzmin, 10 June 2017 - 1312 PM.


#42 GARGEAN

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Posted 12 June 2017 - 1315 PM

What is the performance of 115mm AP rounds? Only I was reading an account of a hit in this area from a 115mm round on an Israeli Centurion which similarly penetrated, just wondering if its a similar level of performance.

If 3BM4 - probably worse against zeroed target and comparable/better against highly angled. Plus bigger drag so worse long range performance. But after armour should be MUCH greater due to some moments of early steel APFSDS rounds.

#43 Stuart Galbraith

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Posted 13 June 2017 - 0636 AM

Yeah, David Isby claimed in his 'Weapons and Tactics of the Soviet Army' that the Israelis considered the 115mm gun, at least at short to medium range, to be a better gun than the 105mm. An fact i gather they DID penetrate Chieftains in the Iran/Iraq war, despite the Chieftain having a range advantage over it. Poor operation probably didnt help of course.



#44 Przezdzieblo

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Posted 14 June 2017 - 1429 PM

 

after hit on photo mantlet was cracked, for repair you will need new mantlet, new gun cradle and 300 hours of work

 

i haven't seen any reports about 115mm APFSDS behind armour effect, but all wars near Israel have so much myths... 

 

btw, L15A2 was used in this test, and maybe i will get something about L23A1, but not L23

 

 

Looks like WO 194/466. It is a nice report that is not only gives a hint about hit results but also about logistic asspect of recovery of damaged vehicle. Plus nice examples of FVRDE pictorial code in right upper corner.

 

 

 

Found something from Dec 1979 on XL23E1, labelled as "512 mm" (body? penetrator itself?), W-Ni-Cu, for gun with pressure of 26 tsi. There were also discussed few more rounds: W-Ni-Cu 512 mm (33 tsi, for MBT-80 gun); W-Ni-Fe and DU of 512 mm (26 and 33 tsi) and two W-Ni-Fe and DU of 650 mm (26 and 33 tsi).

XL23 programme (there is also known another designation, XL22, the most probably earlier) seems an offshot of trilateral gun trials. US shared some part of their APFSDS technology with UK; penetrator that "won" in 1976 shooting from L11 gun was US-orgin. W-Ni-Cu was firstly prefered because older APDS could be utilised.


Edited by Przezdzieblo, 14 June 2017 - 1446 PM.


#45 Wiedzmin

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Posted 15 June 2017 - 0131 AM

 

Found something from Dec 1979 on XL23E1, labelled as "512 mm" (body? penetrator itself?)

 

-2fpYuVL8ww.jpg

 

i think penetrator itself.

 

 

 

 

XL23 programme (there is also known another designation, XL22, the most probably earlier) seems an offshot of trilateral gun trials. US shared some part of their APFSDS technology with UK; penetrator that "won" in 1976 shooting from L11 gun was US-orgin. W-Ni-Cu was firstly prefered because older APDS could be utilised.

 

 

what year of trilateral gun trials with UK APFSDS ? i remember you posted something about 1974, with UK APDS L15A4

 

btw read some report about ATGM trials, swingfire, tow, milan(103mm) and vigilant, is there any good info about milan penetration ? because even this report contain only penetration path in nato heavy triple for milan and nato single medium target, no "simple RHA" penetrtaion



#46 Stuart Galbraith

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Posted 15 June 2017 - 0226 AM

Correct me if Im wrong (I probably am) but wasnt the trilateral gun trials with a British 110mm gun?  I cant recall if they built it or not, but ive a feeling they built at least one working prototype. They had pretty much pulled the plug on it by 1976 or so, if DEFE 48/240 'A study of Future Main Battle Tank Options to replace Chieftain' is any guide.



#47 Przezdzieblo

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Posted 15 June 2017 - 0531 AM

In 1975, during the first round of trilateral trilas, both US and UK tested new APFSDS projectiles. The first one was XM774 model 28, the second - 110 mm projo with US core. Both were only considered as growth potential and as such did not count into official results, leaving FRG as a winner, but also convincing US that the next round of trials could be useful.

In 1976 UK tried new APFSDS and L11 combo which has shown the best performance in terms of armour penetration. Hence US gave UK more time to develop the new 120 mm gun - EXP-M13A.

In late 1977 there were the last round of trilas in USA. UK and FRG rounds gave almost the same performance, UK HEAT failed. FRG won on system maturity ground (officially).



#48 Wiedzmin

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Posted 15 June 2017 - 0558 AM

btw what was the penetration(at 0, at 60 for 2km?) for XM774 ? serial round doesn't look to have good l/d 1/14 - 1/16 or so ? 


Edited by Wiedzmin, 15 June 2017 - 0558 AM.


#49 Wiedzmin

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Posted 26 June 2017 - 1717 PM

This is interesting stuff. Did you ever find any dispersion data for L23?

L23A1 

cgf4Rheqnb0.jpg

 

i also have penetration, but don't understand it at moment, they fired at 130mm single plate, but get 482mm at PB and 435 at 2km



#50 Stuart Galbraith

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Posted 27 June 2017 - 0659 AM

 

This is interesting stuff. Did you ever find any dispersion data for L23?

L23A1 

cgf4Rheqnb0.jpg

 

i also have penetration, but don't understand it at moment, they fired at 130mm single plate, but get 482mm at PB and 435 at 2km

 

 That looks to be broadly 450 RHA, which is about what I thought it is. This is highly significant if true, because it means what I supposed L26 and L27 are might be true also. Hmm, good news. Or at least, better than Ive been assured it was.

 

Thanks for that. Im not remotely technically minded to comment on how good this is, how does it compare to american 105mm rounds of the same period?


Edited by Stuart Galbraith, 27 June 2017 - 0700 AM.


#51 Wiedzmin

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Posted 27 June 2017 - 0726 AM

 That looks to be broadly 450 RHA, which is about what I thought it is. This is highly significant if true, because it means what I supposed L26 and L27 are might be true also. Hmm, good news. Or at least, better than Ive been assured it was.

 

 

Thanks for that. Im not remotely technically minded to comment on how good this is, how does it compare to american 105mm rounds of the same period?

 

well if round penetrate 435(path of round inside angled target) at 2km, i think at vertical plate it will penetrate less than 435(long rod penetrate more at angled targets) 

vtTxVR0rf_s.jpg

 

it's interesting to find more about L23A1 vs 150mm/60 ect, but no info for now...

 

compare to 105mm, i don't know how much M774 can penetrate, but L23A1 better than M735 and M111 imho 


Edited by Wiedzmin, 27 June 2017 - 0731 AM.


#52 RoflSeal

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Posted 28 June 2017 - 1433 PM

What document is this from?



#53 methos

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Posted 29 June 2017 - 0527 AM

This is a very odd table. Just looking at the penetration at 0 km when firing the round from a new gun at +34°C... 

A 490 mm penetration path would require a 130 mm steel plate to be sloped at 75° (at 74° the line of sight is only 471)! So did they actually use a 130 mm plate sloped at 75° or am I misunderstanding the table? Because according to Lanz-Odermatt, the penetration values of APFSDS ammunition against 75° slope are about ~35% larger than against 0° slope.



#54 Wiedzmin

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Posted 29 June 2017 - 0607 AM

What document is this from?

120mm Report for Preliminary Acceptance Annex J pp 1-6

 

This is a very odd table. Just looking at the penetration at 0 km when firing the round from a new gun at +34°C... 

A 490 mm penetration path would require a 130 mm steel plate to be sloped at 75° (at 74° the line of sight is only 471)! So did they actually use a 130 mm plate sloped at 75° or am I misunderstanding the table? Because according to Lanz-Odermatt, the penetration values of APFSDS ammunition against 75° slope are about ~35% larger than against 0° slope.

yes it's very strange test, and seem to be 75°, + don't know right term in english heading angle(?) +- 13-16°(left and right), but it used to imitate T-72 glacis, so it must be in 68-70° range.

 

but if i find more "standard" penetration test i will post it 



#55 Wiedzmin

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Posted 13 September 2017 - 1603 PM

RB2HGGiYrCs.jpg

 

L23A1 core  Tungsten-Nickel-Copper (W.Ni.Cu - S.T.A) overall shot length 510mm

 

Total Weight 7,89kg

Sub-Projectile Total Weight 3.89kg

Penetrator

Material S.T.A.

Weight 3.69 kg

Length 410 mm

Diameter 29.0 mm

L/D Ratio 14.1 : 1

Muzzle Velocity - (From Lll Gun using L8A1 Charge)

 

Velocity Drop (m/s/1000 m) 55 

 

 

New Gun

-33C- 1494 m/s

+21C 1549 m/s

+52C  1587 m/s

 

 

! So did they actually use a 130 mm plate sloped at 75° or am I misunderstanding the table? 

don't know about 130 at this moment, but for 150mm, yes, it's have 71 and 74,8 ° (when testing BD26)


Edited by Wiedzmin, 16 September 2017 - 1514 PM.


#56 Old ROF

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Posted 18 September 2017 - 1311 PM

...

In 1976 UK tried new APFSDS and L11 combo which has shown the best performance in terms of armour penetration. Hence US gave UK more time to develop the new 120 mm gun - EXP-M13A.

....

 

Missed this the first time but the designation should be the EXP19-M13A.

The ordnance development work was to enable the gun system to match the mounting and C-of-G configuration / limitations required to suit the XM1.






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