Did the US test the 88/L71?

[Mobius]

Or did they just use German gun table data?

Curiously the data sets match if you corrected for meters to yards.

 

Spielbergers data_____Aberdeen data

Range____0°(30°)___Range_0° (30°)

0m________________ 0yd___225(198)

100m__220(203)___

500m__205(182)___500yd__207(182)

1000m_186(167)__1000yd__190(167)

1500m_170(150)__1500yd__174(153)

2000m_154(135)__2000yd__159(139)

 

you decide.

[C.G.Erickson]

Or did they just use German gun table data?

Curiously the data sets match if you corrected for meters to yards.

 

Spielbergers data_____Aberdeen data

Range____0°(30°)___Range_0° (30°)

0m________________ 0yd___225(198)

100m__220(203)___

500m__205(182)___500yd__207(182)

1000m_186(167)__1000yd__190(167)

1500m_170(150)__1500yd__174(153)

2000m_154(135)__2000yd__159(139)

 

you decide.

US did test 88/71...got test results.

[Mobius]

US did test 88/71...got test results.

Could you post them?

I thought this book I just found had them but may have snuck in German data.

[C.G.Erickson]

Could you post them?

I thought this book I just found had them but may have snuck in German data.

Mobius

 

The tests with the 88/L71 were to compare the 88 with the US 90mm.

 

Both guns were tested against these Armors:

 

3 3/8" plate at 55 degree obliquity (Sound Familiar? Panther Front Plate)

5" plate at 45 degree obliquity

5" plate at 30 degree obliquity

5" plate at 20 degree obliquity

6" plate at 30 degree obliquity

8" plate at 0 degree obliquity.

 

German projectile tested was APCBC

US 90 mm rounds were 90mm M82, 90mm M77, and 90mmT33

 

C.G.

Edited April 17, 2009 by C.G.Erickson

[C.G.Erickson]

Criteria for comparison tests were established as such:

 

1: A ballistic limit was considered to be the average of a partial and a complete penetration whose velocities were not more than 100 feet per second apart, the partial penetration at the lower velocity.

 

2: An Army complete penetration was obtained when a hole was produced which was permitted the passage of light.

 

3: A Navy complete penetration was obtained when the entire projectile passed through the plate and remained in effective bursting condition, the cavity of the projectile remaining intact.

 

4: A projectile complete penetration was obtained when any plate or projectile fragments were thrown from the rear of the plate with sufficient force to penetrate one inch plywood screen, placed three feet to the rear and parallel to the plate.

 

This test was so important that all other tests with German AT rounds were placed on the back burner allowing 88 mm Tests to be the number one priority.

 

C.G.

Edited April 17, 2009 by C.G.Erickson

[Mobius]

Those would be important tests. Together with the Bojan tests would give an idea of all types of comparisons.

[C.G.Erickson]

Also important was mils deflection at range. 88L71 had 1 mil deflection out to 3050 meters with 42 mils elevation for HE round. Half that for AP.

 

C.G.

[C.G.Erickson]

Those would be important tests. Together with the Bojan tests would give an idea of all types of comparisons.

 

What are Bojan tests?

[Mobius]

What are Bojan tests?

The Yugoslav tests of the 1950s.

They too compared the US 90mn with the 88mm/L71.

http://208.84.116.223/forums/index.php?showtopic=18562

Edited April 17, 2009 by Mobius

[C.G.Erickson]

The Yugoslav tests of the 1950s.

They too compared the US 90mn with the 88mm/L71.

http://208.84.116.223/forums/index.php?showtopic=18562

Worthless without quantifying factors. You might as well say, that personally, I can throw a dirt clod through a knot hole if the conditions are right.

 

Ask yourself this. Why did Americans compare 3 types of ammo for the 90, with one being experimental, against the standard German AT projectile?

 

C.G.

[Przezdzieblo]

German seem to be better?

 

 

For me more interesting would be if there was any influence of German tank ordnance on US guns and ammo projects. Aside of high velocity HVAP, HVAP-DS and the "arrow" projectiles there probably were also more conventional APC rounds developed. Found designation 90 mm APC-T T50 - I guess it was tested in 50`s, maybe also was tried to replace WWII-era AP T33 (M318).

 

 

US 90 mm rounds were 90mm M82, 90mm M77, and 90mmT33

and

Why did Americans compare 3 types of ammo for the 90, with one being experimental...

Question: 3 types including experimental? Did T33 (unstandarized) was that experimental one? I though there was mentioned somewhere on TN that there was tried also 90 mm APDS early after the war - and I do not mean sabot later called T65, tested for M3 gun upgrading and new T119.

 

 

 

P.S. Is not that "worthless" a way to stron description? bojan mentioned the criteria that test was based upon. It is not US Army Ballistic Limit, nor US Navy Ballistic Limit, but looks clear enough. 50% of complete penetrations counts, only "fair hits", at least 50% of mass passed the armor (somehow similar to US Protection Ballistic Limit), up to 1000 meters guns tried vs armour "life", above 1000 meters velocity changed by power of charge changed, etc. Much more than no ballistic test criteria.

Edited April 17, 2009 by Przezdzieblo

[Mobius]

Worthless without quantifying factors. You might as well say, that personally, I can throw a dirt clod through a knot hole if the conditions are right.

C.G.

C.G. will you post the actual penetration numbers?

[alejandro_]

Russians tested 88L71 and fired at a captured Panther. Front armour (85mm@55°) was penetrated from 650 meters.

[jwduquette1]

Worthless without quantifying factors. You might as well say, that personally, I can throw a dirt clod through a knot hole if the conditions are right.

 

Ask yourself this. Why did Americans compare 3 types of ammo for the 90, with one being experimental, against the standard German AT projectile?

 

C.G.

 

Hi Carey:

 

I think worthless is too strong a description, but I understand where you may be coming from. My own problem with the Yugo testing is the lack of critical detailing required in developing any accurate sense for either limit obliquity -- limit range -- or limit velocity. The sort of detailing one normally finds in similar tests regimes conducted by UK, USA, and Germany during this same time frame. The Yugo tests are very interesting to look at, but I stopped sometime ago trying to draw anything out of the materials aside from generalizations. Going any further with the materials -- at least in my mind -- requires actual shot-by-shot ballistic test records. Whether or not that level of detail exists is yet to be seen.

 

Best regards

Jeff

[C.G.Erickson]

Hi Carey:

 

I think worthless is too strong a description, but I understand where you may be coming from. My own problem with the Yugo testing is the lack of critical detailing required in developing any accurate sense for either limit obliquity -- limit range -- or limit velocity. The sort of detailing one normally finds in similar tests regimes conducted by UK, USA, and Germany during this same time frame. The Yugo tests are very interesting to look at, but I stopped sometime ago trying to draw anything out of the materials aside from generalizations. Going any further with the materials -- at least in my mind -- requires actual shot-by-shot ballistic test records. Whether or not that level of detail exists is yet to be seen.

 

Best regards

Jeff

 

Hey Jeff

 

You're right, worthless is a bit strong. That was my Tom Jentz side coming out

 

Thats what I love about Aberdeen Tests. Probably the most thorough of any tests I have seen. Individual shot tabulations. Photo's of recovered projectiles from each shot. etc...etc...

 

C.G.

[Mobius]

2: An Army complete penetration was obtained when a hole was produced which was permitted the passage of light.

What was an Army partial penetration?

Maybe it anything that was within 100 f/s that wasn't a complete penetration?

[alejandro_]

http://bp1.blogger.com/_CbwnjooteyI/R2AYqf...-hull-holed.jpg

 

http://bp3.blogger.com/_CbwnjooteyI/R2AYf_...r-hull-90mm.jpg

 

90mm tests on Panther.

 

From this blog:

 

http://anonymous-generaltopics.blogspot.co.../label/Char%20B

 

I don't want to go off-topic, can anyone tell which Panther model is this? looks Ausf D

 

http://bp0.blogger.com/_CbwnjooteyI/SA9iPk...h/panther_7.jpg

[jwduquette1]

What was an Army partial penetration?

Maybe it anything that was within 100 f/s that wasn't a complete penetration?

 

No. A partial penetration -- in the case of determining an Army Limit BL(A) is any shot result that doesnt result in light passage through the plate or if the projectile lodges the nose can be visible on the back side of the plate.

 

Your mixing up how a limit velocity is determined with how CP or PP is defined. There is no velocity component associated with the definition of either CP or PP. The velocity bracket is used for defining limit velocity. Morover, the range of usuable mixed results will be defined within the test specification by a specific velocity bracket. A partial penetration (PP) could occur at 500-fps from the closest CP result and it would still be a PP.

Edited April 17, 2009 by jwduquette1

[C.G.Erickson]

German seem to be better?

For me more interesting would be if there was any influence of German tank ordnance on US guns and ammo projects.

Why did Americans compare 3 types of ammo for the 90, with one being experimental...

Question: 3 types including experimental? Did T33 (unstandarized) was that experimental one? I though there was mentioned somewhere on TN that there was tried also 90 mm APDS early after the war - and I do not mean sabot later called T65, tested for M3 gun upgrading and new T119.

Prz

 

All German projectiles were better than what the US had at that time. German influence? Testing report summary suggested US metallurgy, hardening standards should be made exactly to German specs.

 

Sabot Round for 90mm? I have a video of 90mm gun shots against a Panther from 200 yards. They fired M77, and what appeared to be 3 Sabot rounds. There was no date on the video, but the uniforms of the ordinance officers were WW2. I disscussed this with Dick Hunnicut and he watched the video with me and he was puzzled as he didnt have any records of US 90 sabot development for that period.

 

C.G.

[C.G.Erickson]

http://bp1.blogger.com/_CbwnjooteyI/R2AYqf...-hull-holed.jpg

 

http://bp3.blogger.com/_CbwnjooteyI/R2AYf_...r-hull-90mm.jpg

 

90mm tests on Panther.

 

From this blog:

 

http://anonymous-generaltopics.blogspot.co.../label/Char%20B

 

I don't want to go off-topic, can anyone tell which Panther model is this? looks Ausf D

 

http://bp0.blogger.com/_CbwnjooteyI/SA9iPk...h/panther_7.jpg

First photo of Panther in the 90mm tests is not strikes from a 90mm. 17lber Sabot shots.

The Panther from the other site is indeed a Panther D.

[rmgill]

And given that there's a Brit Vickers 3.7HAA gun and mount at Aberdeen has me wondering if they tested that gun system as well for AT work.

[jwduquette1]

And given that there's a Brit Vickers 3.7HAA gun and mount at Aberdeen has me wondering if they tested that gun system as well for AT work.

 

Maybe you already know this, but the British tested the armor penetrating capability of their 3.7" HAA. Pretty good performance as I recall -- better than the 88mm Kwk36 (pzgr with small bursting charge). It could have been a nice weapon for the 8th Army to use in an antitank role in N.Africa.

 

Or were you interested in contrasting Shoeburyness results with Aberdeen?

Edited April 17, 2009 by jwduquette1

[C.G.Erickson]

Lets look at the metallurgy of the 88mm projectile.

 

Type: APCBC

Weight: 22.3 lbs

Driving Band: Cu and Fe

Fuze type: Centrifugal arming

Explosive Filler: TNT

 

Main Body Chemical Analysis

C-----Mn-----Si-----S-----P-------Cr-------Cu-----Al-----Ni-----V-----Mo

.58---.78----.96---.02---.017----1.13-----.065----0------0-----0------0

Hardness Rockwell Scale: 28-54

Similar US Steel: WD5150

Manufacture: Forged. Machine finished. Uniform heating. Oil Quench or water. High base draw.

 

Armor Piercing Cap Chemical Analysis

C-----Mn-----Si-----S------P-----Cr-----Cu-----Al-----Ni-----V-----Mo

.52---.97----.81---.02---.028---1.20---.15------0-----0------0-----0

Hardness Rockwell Scale:39-54

Similar US Steel: WD 5150

Manufacture: Pierced,Machined-uniform heating followed by uniform quench and differential base temper.

 

C.G.

[Mobius]

Lets look at the metallurgy of the 88mm projectile.

 

Type: APCBC

Weight: 22.3 lbs

Driving Band: Cu and Fe

Fuze type: Centrifugal arming

Explosive Filler: TNT

 

Main Body Chemical Analysis

C-----Mn-----Si-----S-----P-------Cr-------Cu-----Al-----Ni-----V-----Mo

.58---.78----.96---.02---.017----1.13-----.065----0------0-----0------0

Hardness Rockwell Scale: 28-54

Similar US Steel: WD5150

Manufacture: Forged. Machine finished. Uniform heating. Oil Quench or water. High base draw.

 

Armor Piercing Cap Chemical Analysis

C-----Mn-----Si-----S------P-----Cr-----Cu-----Al-----Ni-----V-----Mo

.52---.97----.81---.02---.028---1.20---.15------0-----0------0-----0

Hardness Rockwell Scale:39-54

Similar US Steel: WD 5150

Manufacture: Pierced,Machined-uniform heating followed by uniform quench and differential base temper.

C.G.

 

Thanks, C.G. But the penetration at 1000yd is?

[KingSargent]

Maybe you already know this, but the British tested the armor penetrating capability of their 3.7" HAA. Pretty good performance as I recall -- better than the 88mm Kwk36 (pzgr with small bursting charge). It could have been a nice weapon for the 8th Army to use in an antitank role in N.Africa.

They would have to put sights on it first. Many other factors kept it an AA gun.