Talk:76 mm gun M1

Wikified Table, Before reorganization

Published Source	Gun Type	Ammunition	Penetration at range
			500 m	1000 m
Foss, Chris, Artillery of the World, 1974	Soviet 85 mm	Standard Armour-Piercing High-Explosive (APHE)	N/A	102 mm
		High-Velocity Armour-Piercing (HVAP)	N/A	130 mm
Bovington Tank Museum, Fire and Movement, 1975	Soviet 85 mm	Armour-Piercing Capped Ballistic Capped (APCBC)	103 mm	94 mm
	US 76 mm	APCBC	94 mm	89 mm
		HVAP	158 mm	134 mm
Hunnicutt, R. P., Sherman: A History of the American Medium Tank, 1978	US 76 mm	Armour-Piercing Capped (APC) M62	93 mm	88 mm
		HVAP M93	157 mm	135 mm
Woodman, Harry, Tank Armament in World War Two, 1991	Soviet 85mm	APC	96 mm	88 mm
		HVAP	121 mm	80 mm
	US 76 mm	APCBC	94 mm	89 mm
		HVAP	158 mm	134 mm
Zaloga, Steven J. and Grandsen, James, Soviet Tanks and Combat Vehicles of World War Two, 1984	Soviet 85 mm	APHE (BR-365)	111 mm	102 mm
		Armour-Piercing, Composite Rigid (APCR) (BR-365P)	138 mm	100 mm
Zaloga, Steven J. and Sarson, Peter, Sherman Medium Tank, 1993	US 76 mm	APC (M61)	98 mm	90 mm
		HVAP (T-4)	150 mm	132 mm

This table is the wikification of the previous text block. When wikifying, I first created this table and then decided to reorganize it. The wikified (but never saved) table is the above. –Dvandersluis 17:34, 5 July 2006 (UTC)

this table miss relative angle to fall of projectiles, on line are available after war yugoslavian test that show near same penetration for soviet 85mm and US 76mm (comparing AP with AP and HVAP and HVAP (APCR)) —Preceding unsigned comment added by 95.246.239.4 (talk) 01:44, 4 May 2011 (UTC)

Redirect proposal

I propose that we redirect this to a "76 mm gun (US)" or similarly named page that includes the AA and 3 inch M7 guns too. Thank you.Wikist 14:42, 10 November 2006 (UTC)

You mean you want to merge the article with 3-inch M1918 gun ? I don't think it's good idea. Bukvoed 12:29, 21 November 2006 (UTC)

Yes, because both are short articles they share a family tree (M1 uses the same shell as the M7 that is on the other page and so M7 penetration is here on the M1 page). We might even add the M32 to avoid an M32 stub article (see how M6 is on 75 mm Gun (US).Wikist 19:40, 22 November 2006 (UTC)

For what it is worth, I agree with Bukvoed. It seems illogical to place the M1 into the same article as the M7 since they used very dissimilar complete rounds. The fact that they used the same projectile is a separate issue based solely on the need to rush the M1 into production, and does not seem sufficient reason to "join" them in the same article. On a related note I should point out that the penetration chart does not include the figures for the most common combat ranges over 1,000 yards.14thArmored 1500 Hours 22 November 2006

Question regarding caliber

I've read several places that the M1 gun on the upgraded M4 was in fact a 76,2mm gun, even though it's called a 76mm gun. Is this accurate?(No, I'm not confusing it with the 17 pounder)83.109.86.72 (talk) 15:57, 25 February 2008 (UTC)

Data table is a complete mess

There should be no datat for 85mm for the 1st two strings IMO. During wartime, 85mm didn't have any APC or APCBC, just plain AP/HE and APCR (those listed below). And post-war shells had much better penetration. —Preceding unsigned comment added by 80.82.36.128 (talk) 05:22, 8 January 2009 (UTC)

There are almost No dates listed in the article

I understand that getting the exact dates that the 76mm gun replaced the 75mm gun is extremly difficult, but, I did not read about when the new tank gun was put into production anywhere in the article. Was it 1942, 1943 or 1944? I think the article could be improved by giving a more detailed time frame, such as at least giving the year the 76mm gun replaced the 75mm as the main tank gun of the M4 Sherman. Thank you. 204.80.61.110 (talk) 13:30, 19 August 2011 (UTC)Bennett Turk

What is this supposed to mean?

"the subsequent uparmoring of these AFVs to 80 mm and upgunning to the KwK 40/StuK 40 diminished the ability of the Sherman to engage at long distances, whereas the Sherman front hull could provide a very effective backstop."

This sentence makes no sense to me. The Sherman hull could be very easily penetrated by the KwK 40, which doesn't seem to fit any definition of "effective" I'm familiar with.--FergusM1970^{Let's play Freckles} 11:53, 15 December 2014 (UTC)

I agree, I`ve removed it. May we ask anyone wanting to replace that to define "backstop", I assume the original writer wasn`t trying to imply the Sherman had adequate armour for a KwK 40--JustinSmith (talk) 18:58, 28 December 2014 (UTC)

76mm "equal" to the 17pdr.

The article states :
(the 76mm) "was roughly equal with the 17pdr"
What evidence is there for that ? Every book I`ve read on the subject states that the 17pdr was a superior anti tank weapon to the 76mm. And since the 76mm was introduced as an anti tank weapon surely that`s the be all and end all ?--JustinSmith (talk) 18:56, 28 December 2014 (UTC)

The 17 pdr page states: The Firefly 17-pounder was able to penetrate some 140 mm (98 mm)of armour at 500 m (550 yd) and 131 mm (88 mm) at 1,000 m (1,100 yd) using standard Armour Piercing, Capped, Ballistic Capped (APCBC) ammunition at a 30-degree angle. Armour Piercing, Discarding Sabot (APDS) ammunition could penetrate some 209 mm (139 mm) of armour at 500 m and 192 mm (127 mm)at 1,000 m at a 30-degree angle, which on paper could defeat the armour of almost every German armoured fighting vehicle at any likely range.[citation needed] I put the "equivalent shell" 76 mm values (in brackets). The 17 pdr is clearly superior to the 76 mm gun which is hardly surprising given the massive shells used, BUT "citation needed" — Preceding unsigned comment added by 194.72.161.50 (talk) 10:58, 11 June 2015 (UTC)

The 17 pdr cartridge actually contained a larger propellant charge than the 90 mm Gun M1/M2/M3. — Preceding unsigned comment added by 95.150.100.224 (talk) 10:05, 29 July 2016 (UTC)

The 90mm sctially generated more energy than the 17 pdr: 1308 foot tons/3532 kilojoules versus 1,148 foot tons/3,100 kilojoules. Jdnwiki2016 (talk) 00:22, 10 December 2016 (UTC)

The 17 pdr cartridge contained as much propellant charge as the cartridges of both the 90 mm and the 75 mm Gun M2/M3/M6 combined.

The 17 pdr with APDS would knock out anything it was fired at, at almost any range, and few of the 17 pdr's users would have swapped them for anything else. — Preceding unsigned comment added by 95.149.173.13 (talk) 14:42, 12 March 2017 (UTC)

7.3 lb + 2.2 lb = 9.5 lb > 9 lb. The previous comments were in response to misleading statements concerning powder capacity and energy, not penetration. — Preceding unsigned comment added by 2600:387:1:811:0:0:0:74 (talk) 23:45, 2 February 2018 (UTC)

World of Tanks a RS?

This appears to be a forum based on an online game. It is a totally unreliable, unacademic source. The performance of the 76mm seems wildly overstated. I have mentioned this before, and the author's apparant hatred of the 17 pdr, which was the best Allied anti tank gun of the war. The comparison with the Firefly is absurd. I suggest we discuss this to gather consensus for speedy removal. 2500m?? No way. Strongly advise removal so as not to mislead casual readers. I note it has been removed before and replaced without discussion. Irondome (talk) 00:45, 21 January 2015 (UTC)

I strongly agree with you concerning our content guidelines of WP:V and WP:RS. But it seems that the Author using primary sources and giving just the predictive calculated probability. It is very unlikely and nearly expelled to hit the lower hull over 2000 m in a tank versus tank combat. The attempted shot rather would glance off the glacis. Zaloga describe that the Firefly opened fire only below 1200 yards, however, an antitank cannon waited in ambush might have a chance to place that shot, but not over 2500 yards. Bouquey (talk) 03:20, 21 January 2015 (UTC)

Then I take it that you agree with deletion and replacement with a RS like Zaloga? I do not think this is a reliable secondary source. Anyone can publish primary sources on a blog or forum, but I think we would both prefer to see it in a reputable serious publication. It does make some strange claims also, apparently WP:OR and WP:SYNTH which only a reputable published author could get away with. Appreciate the feedback! Regards Irondome (talk) 03:27, 21 January 2015 (UTC)

Unfortunately, I don't have Zaloga's book which mentioning it explicit, I rather caught it once on Google book search. Hopefully someone else could quote him. Well, I would suggest to proceed it like we have made with the Wa Pruef quotes and rewrite it with a clear please note of an estimation for the contrast. Many thanks to consider my feedback :) Bouquey (talk) 03:48, 21 January 2015 (UTC)

I agree and have deleted it. Hardly any tank v tank engagements took place at 2500yds, so it`s misleading and irrelevant anyway.--JustinSmith (talk) 13:49, 21 January 2015 (UTC)

Hi JustinSmith, thanks for the speedy deletion of the disputed passage. As Irondome already pointed, I would also prefer to see the quotes from a verifiable and reputable publication with the authors expertise, since the primary given source at the blog isn't accessible. However I still belive that a moderat and more objective rewrite could actually fit and being used to contrast the estimated probabilities of those engagements. But for that, its also crucial to have the acutal ref. that common battle engagements did not occurred above 1500 yards. Which seems to be manageable. Regards Bouquey (talk) 14:54, 21 January 2015 (UTC)

T1 vs M1 designations

The current variants summary is:

Variants

M1: 57 caliber long gun[5]

M1A1: 52 caliber long version of gun with breech counterweight.[6]

M1A1C: fitted with muzzle brake

M1A2: fitted with muzzle brake

Zaloga's comment on page 4 of Sherman 76 that indicates that the shortened gun was the M1A1 conflicts with Hunnicut (Sherman: A History of the American Medium Tank) on pages 198-204, (especially 200, 204, 206, 207). Hunnicut states that the second test gun with a shorter barrel was adopted as the M1 (page 200 caption for picture of shortened T1). He indicates these as proper models:

Variants

T1: first production test gun 57 caliber long gun, second test gun 52 calibers long

M1: 52 calibers long

M1A1: 52 caliber long version of gun with longer recoil surface to allow lugs for trunion to be moved forward

M1A1C: Threaded for muzzle brake

M1A2: Threaded for muzzle brake and rifling twist changed from 1:40 calibers to 1:32 calibers. — Preceding unsigned comment added by JDNatWiki (talk • contribs) 14:49, 4 May 2016 (UTC)

3-inch gun source

The 3-inch guns M5, M6, and M7 were derived from the 3-inch gun M3, in particular the T9 model which was cancelled in 1938 and replaced by the 90-mm gun. — Preceding unsigned comment added by JDNatWiki (talk • contribs) 20:33, 5 May 2016 (UTC)

The reference to the M7s origin served no purpose so I removed it.JDNatWiki (talk) 15:38, 6 May 2016 (UTC)

17pdr vs 76-mm cartridge comparison

This is an FYI for any future researcher: Doubtlessly the references to the weight of powder for 17pdr vs 76-mm is taken from Zaloga's M4 (76). It isn't wrong as such but Zaloga isn't aware of powder weight vs. powder type situation. As shown on pages 564, 565 and 567 of Hunnicutt's Sherman opus the 17 pdr and 90-mm have almost the same chamber capacity of 300 cubic inches which is a bit more than twice the size of the 76s 140 cubic inches. I have seen varying quotes but basically the 76-mm has a 3.5 or 3.6 lb. powder charge which is about half the powder of the 90-mm's 7.2 to 7.3 lb. load. The 3-inch gun (the case is not completely filled by the powder used) gives the same ballistics as the 76-mm with a 4.5 to 4.7 pound charge - which is about half the weight of Zaloga's quote of 9 pounds for the 17pounder. I wish there was a verifiable source where someone either explained that this was a wrong comparison or allow researchers to say something simple like "The 17pounder has roughly twice the powder capacity and accounting for powder density and type twice the powder of the 76-mm". TM 9-1901 Artillery Ammunition June 1944 and The American Arsenal both give powder charge quoted for most basic WW II US rounds and illustrate how the 3-inch cartridges are partially empty. JDNatWiki (talk) 01:17, 9 May 2016 (UTC)

Rifling twist change, tungsten shot development

As an addendum to the previous, the University of New Mexico, in researching tungsten loads for the Ordnance Department 1943-44, loaded the 76-mm case with 4 pounds of M2 powder and boosted velocity 200 feet per second as a test. Not all powders are the same. See page 117, 109 of ADA800118 Work on Sabot Projectiles 1942-1944. This document also mentions the rifling change for the 76-mm page 108 footnote and gives details concerning tungsten shot starting about page 105.

Following is the Army's very brief intro page with a pdf download link.

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA800118

JDNatWiki (talk) 01:18, 9 May 2016 (UTC)

For comparison the propellant used in a British weapon such as the 17 pdr was cordite. IIRC, firing APDS the 17 pdr's muzzle velocity was approaching 4,000 fps - something like 3,900 fps. — Preceding unsigned comment added by 95.149.241.62 (talk) 20:50, 24 June 2016 (UTC)

Standard 75 mm Gun M2/M3/M6 as used in the Grant and Sherman had a cartridge containing around 1 lb of propellent. 76mm M1 around 3.6 lbs of propellent. 17 pdr almost 9 lbs of propellent. [1] — Preceding unsigned comment added by 2.30.162.221 (talk) 19:02, 28 June 2016 (UTC)

The US 75s were loaded with 2.16 pounds/2 kilograms of propellant per American Arsenal page 275 or 2 pounds/.9 kilograms per TM 9-1901 Artillery Ammunition page 356. If you had read a more recent book like Armored Thunderbolt page 99 you would see that Zaloga has realized his mistake and as such you would not be 13 years behind the learning curve. Likewise he has stopped calling the M64 white phosphorous round the M89 (which was a pure smoke). Nor has he repeated (not that I have found) the statement on page 4 of M4(76mm) where he claimed the 76mm and 17pounder projectiles "weighed about the same". The 17 pounder AP weighed 10% more than than the 76 AP shot giving it 10% more penetration at any given velocity; and the 17 pounder had over 12% more velocity. In Armored Thunderbolt the Heavy Tank Guns table page 121 quotes high velocity tungsten shot velocities and penetration for basic 88 AP shot in comparison to basic 90mm shot (see page 336 for 90mm APCR penetration.) The same propellant charge is given for both 88s; the wrong projectile designations are used; the AP shot was heavier. On pages 99 and 106 he states that the 75mm M3 barrel was 32 calibers long; the bore length was 37.5 calibers and overall length 40.1 calibers. I learn a lot about usage from him but his technical data is unreliable. Quoting Zaloga for technical statistics - especially his old books - is a fool's folly.Jdnwiki2016 (talk) 01:30, 10 December 2016 (UTC)

Proper comparison of 17pdr to 76-mm cartridge comparison

Zaloga is a poor resource for any sort of technical detail. His attempt to compare cartridges by barrel length and powder charge in his books is a waste of printing ink: unless the exact same propellant type is used then the weight of the powder charge means nothing. Even then, the comparison is meaningless without the same caliber, barrel length and projectile weight. The only useful comparison of how powerful the cannon were (besides penetration, quotes of which vary by source) is the projectile weight and muzzle velocity rolled up into foot tons/kilojoules of energy. Using a short ton (2,000 pounds as opposed to the long ton used by Hunnicutt in his books) and a kilojoules multiple of 2.7 per foot ton you find:

The 75-mm M3 firing a 15 pound/6.8 kilogram projectile at 2030 feet/619 meters per second generated 480 foot tons/1,296 kilojoules of energy.

The 76-mm M1 and 3-inch M7 firing a 15.5 pound/7 kilogram projectile at 2600 feet/793 meters per second generated 814 foot tons/2,198 kilojoules of energy.

The German 75-mm KwK 42 firing a 15.75 pound/7.2 kilogram projectile at 3050 feet/930 meters per second generated 1,138 foot tons/3,073 kilojoules of energy.

The 17 pounder firing a 17 pound/7.7 kilogram projectile at 2950 feet/900 meters per second generated 1,148 foot tons/3,100 kilojoules of muzzle energy.

The 90 mm firing a 24 pound/10.9 kilogram projectile at 2650 feet/808 meters per second generated 1,308 foot tons/3,532 kilojoules. The improved rounds firing at 2800 feet/854 meters generated 1,460 foot tons/3,942 kilojoules but were not provided until 1945 and in small quantities.

The 76mm had no way of being anywhere near as potent as the 17 pounder. The 17 pounder was pretty much the Allies' opposite to the "Long 75" of the Panther. Both were optimized for antitank performance (for their caliber) while the U.S. cannon were not. Jdnwiki2016 (talk) 02:35, 10 December 2016 (UTC)

Muzzle velocity for a 17 pdr firing APDS was nearly 4,000 feet per second. Projectile after sabot separation was solid tungsten carbide shot. — Preceding unsigned comment added by 95.149.173.13 (talk) 14:47, 12 March 2017 (UTC)

Edit the Wikipedia article on the 17 pounder if you think that data is missing. — Preceding unsigned comment added by 2600:387:1:811:0:0:0:74 (talk) 23:51, 2 February 2018 (UTC)

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Problems knocking out the Panzer IV?

The article says that the 76mm gun had trouble penetrating the upgraded versions of the Panzer IV frontally. However, the PZIV H only has 80mm armour, and the 76mm should be able to punch through that even long ranges, according to the penetration tables. — Preceding unsigned comment added by 77.241.137.71 (talk) 20:23, 2 June 2020 (UTC)

Aberdeen's documents show something different. Instead of pasting dubious all over did you read their report?Tirronan (talk) 04:35, 24 August 2021 (UTC)

So let us start ARDEC is: Armament Research, Development and Engineering Center Overview  ARDEC provides the technology for more than 90 percent of the Army’s lethality and a significant amount of support for other services’ lethality  The center’s civilian engineers, scientists and support personnel leverage the latest technology to design, integrate and support small-, medium- and large-caliber weapons and ammunition systems that arm Soldiers with powerful lethal and non-lethal options.  ARDEC maintains 90-plus R&D laboratory facilities at Picatinny Arsenal, N.J.; Watervliet Arsenal, N.Y.; Rock Island Arsenal, Ill.; and Aberdeen Proving Ground, Md. More than 30 percent of ARDEC technical staff has a doctorate or master’s degree.  ARDEC has won 34 out of 100 Army’s Greatest Inventions awards, as judged by Soldiers, since 2002.  ARDEC supports learning through Armament University, a unique, doctorate-degree granting institution augmented by teachers from academic and military institutions.  Core competencies: warhead/lethal mechanisms and fuzing (energetics, guidance/navigation/control), countermine/IED neutralization, directed energy/non-lethal, fire control.  Major Partners: TACOM, Program Executive Office Ammunition, PEO Soldier, Joint Munitions and Lethality Life Cycle Management Command, PEO Combat Support Here are some of the excerpts from the document:

Situations like Captain Farmer’s created a scramble to obtain upgraded 76-mm tanks. Some started to make their way into service by September, but they were still relatively scarce with only 250 of the 1,913 tanks in the 12th Army Group equipped with 76-mm guns (ref. 14). The Tank Destroyers were the only American vehicles equipped to defeat the German armor while upgraded Shermans slowly trickled in. They fared better but still were not as successful as anticipated. The only way the Panther could be defeated from the front was to deflect a shot off of the mantlet downward onto the armor above the driver’s head (ref. 10). This was the fabled “lucky shot,” and the odds of achieving this effect are extremely unfavorable. It seems inconceivable that a 75-mm projectile would fail to penetrate a target at point blank range. The picture makes sense when taking a look at the physics behind armor penetration. The following formula is the Lambert-Zukas formula for deriving the limit velocity (𝑉𝑙 ), commonly referred to as the V50 (ref. 15). 𝑉𝑙 = ( 𝐿 𝑑𝑝𝑟𝑜𝑗) .15 ∗ 𝛼 ∗ √( 𝑑𝑝𝑟𝑜𝑗3 𝑚𝑎𝑠𝑠𝑝𝑟𝑜𝑗) ∗ [[( 𝑡 𝑑𝑝𝑟𝑜𝑗) ∗ sec(𝜃) .75] + 𝑒 [−( 𝑡 𝑑𝑝𝑟𝑜𝑗)∗sec(𝜃) .75] − 1] (1) 𝑉𝑙 𝐿𝑖𝑚𝑖𝑡 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑜𝑟 𝑉50 𝑡 𝐴𝑟𝑚𝑜𝑟 𝑝𝑙𝑎𝑡𝑒 𝑡ℎ𝑖𝑐𝑘𝑛𝑒𝑠𝑠 𝜃 𝑆𝑙𝑜𝑝𝑒 𝑜𝑓 𝑎𝑟𝑚𝑜𝑟 𝐿 𝐿𝑒𝑛𝑔𝑡ℎ 𝑜𝑓𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑜𝑟 𝑚𝑎𝑠𝑠𝑝𝑟𝑜𝑗 𝑀𝑎𝑠𝑠 𝑜𝑓 𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑜𝑟 𝑑𝑝𝑟𝑜𝑗 𝐷𝑖𝑎𝑚𝑒𝑡𝑒𝑟 𝑜𝑓 𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑜𝑟 𝛼 = 4000 𝑅𝐻𝐴 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 The 𝑉𝑙 is the velocity that penetration occurs 50% of the time for a specific combination of a given projectile against a specific target thickness and obliquity angle. A striking velocity below this 𝑉𝑙 or V50 can be considered the point the projectile will not penetrate the target. The TM 9-1907 lacks any data regarding the Panther, but the Lambert-Zukas 𝑉𝑙 calculation for the M61 75-mm APC against the frontal hull armor of the Panther is calculated as approximately 3700 fps. The front turret does not fare much better at 3200 fps. This is well over the 2030-fps muzzle velocity of the 75-mm gun; failure at point blank is a given. The M10 Tank Destroyer crews discovered in July 1944 that the 3-in. APC shell bounced off of the front glacis plate of the Panther tank at all ranges (ref. 16). The M62A1 was also the primary anti-tank round for the 76-mm M1 Guns, which proved unfortunate for the M18 Tank Destroyer crews. The inability of the 3 in. and 76-mm to penetrate the frontal armor of the Panther sent a shockwave through allied command.

The first appearance in technical data of the top assembly for the 76-mm HVAP-T round was dated January 31, 1945, as the T40E20 (75-1-220), though its individual components are accounted for earlier. The shot, HVAP-T, 76-mm or 3 in., M93 metal parts assembly (75-2-361) was official and approved November 11, 1944. The initial limited fielding in September 1944 carried the T40 designation since the 76-mm HVAP-T round would be designated the M93 only after February 1, 1945. Figure 5 shows an exploded view of the M93 HVAP-T. Figure 5 M93 HVAP-T exploded view The T40E20 (M93) projectile, or “Shot,” consisted of a steel base, aluminum body, tungsten carbide core, nose, windshield, and bourrelet ring. The tungsten carbide core was assembled to the cylindrical opening through the center of the aluminum body. The aluminum nose threads into the mouth of the body, covering the nose end of the tungsten carbide penetrator and holding it in place. The steel base assembles onto the back end of the body, preventing the core from slipping out of the body rearward. The bourrelet ring rests in a recess near the forward end of the body, positioned flush with the circumference of the body. The windshield was threaded onto the forward end of the body, in front of the bourrelet band. This process encapsulates the nose and core and holds the band in place. A tracer in the base of the projectile, ignited by the propellant combustion product, reduces drag. In a similar fashion as the M62A1, this “Shot” assembly uses the M26 case, loaded with 3.9 lb

UNCLASSIFIED

Approved for public release; distribution is unlimited. UNCLASSIFIED 10 of M2 powder and an M28A2 percussion primer. The total weight of the 76-mm HVAP-T round was approximately 18.91 lb with an as-fired weight of the projectile of 9.4 lb.

BALLISTICS MODELING AND CALCULATIONS Velocity Degradation versus Range The first method that was considered for the expected degradation of velocity from muzzle exit over a given range is via hand calculation. This can be represented as a function of the muzzle velocity, or initial velocity (Vo), and the physical properties of the projectile and air. Following this reasoning, the velocity at a given horizontal range (x) can be calculated via the following simplified formula (linear velocity decay formula):

𝑉𝑋 = 𝑉0 − (𝑘2 ∗ 𝑥) (2)

The Constant k2 is derived via the interaction of the projectile cross section and mass with the surrounding air (ref. 15). This constant was chosen because the velocity of the projectile is expected to be 0.8M <Vx< 2.5M for much of its effective range. This is likely a better approximation for the M62A1 APC since its muzzle velocity is in the Mach 2.3 range. The HVAP-T is also within this Mach number range over much of its trajectory, but with a muzzle velocity of 3400 fps, the close ranges exceed Mach 2.5. This introduces error into the assumed linear velocity decay. The validity of this method is also suspect at longer ranges when the striking velocity drops below Mach 0.8. The effect of Mach number/K constant after evaluating just k2 first will be examined as well as the shift in striking velocity decay when accounting for the subsonic and above Mach 2.5 portions of the trajectory. 𝑘2 = [ (𝜌∗𝑆) (2∗𝑚𝑎𝑠𝑠) ] ∗ 𝐾2 ∗ 𝑎 (3) 𝑆 = 𝐶𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 𝑜𝑓 𝑝𝑟𝑜𝑗𝑒𝑐𝑡𝑖𝑙𝑒 𝐷𝑒𝑟𝑖𝑣𝑒𝑑 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 𝐾2 = 0.841 𝐶𝑑 = 𝐷𝑟𝑎𝑔 𝑐𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡 𝐾2 = 𝐶𝑑 ∗ 𝑀𝑀 = 𝑀𝑎𝑐ℎ 𝑛𝑢𝑚𝑏𝑒𝑟 𝑆𝑝𝑒𝑒𝑑 𝑜𝑓 𝑠𝑜𝑢𝑛𝑑 𝑖𝑛 𝑎𝑖𝑟 𝑎 = 1120 𝑓𝑝𝑠 𝑀𝑎𝑠𝑠 𝑜𝑓 𝑃𝑟𝑜𝑗𝑒𝑐𝑡𝑖𝑙𝑒 𝑚𝑎𝑠𝑠 = 11.09 𝑙𝑏 for (M62A1 APC) 𝐴𝑖𝑟 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝜌 = 0.0751 𝑙𝑏/𝑓𝑡3 Attempting to find the velocity at a range of 500 yd, 1,500 ft is inserted for x in the equation. Given that the muzzle velocity for the M62A1 is 2600 fps, the expected velocity at 500 yd is calculated to be 2433 fps. In order to determine the rate of degradation, a series of ranges are evaluated similarly. The predicted velocity degradation over range can now be predicted using the previous equation. Given the velocity curves for each shell, it is determined how each should retain its velocity. Figure 8 contains the two 76-mm (M62A1 and M93) and one 75-mm (M61) anti-tank shells. This plot indicates velocity from muzzle exit to a range of 5,000 yd. The HVAP-T is expected to retain

UNCLASSIFIED

Approved for public release; distribution is unlimited. UNCLASSIFIED 14 a higher velocity over the same given range as its counterparts, except for over a range of 4,200 m. This is not surprising given that it starts out with a much higher muzzle velocity. What is surprising is that the M61 75-mm APC seems to retain its velocity on par with the M62A1 76-mm APC. The lower performance of the 75-mm is likely related to its lower muzzle velocity rather than an issue with the projectile design. The “Y intercept” has also been adjusted to 3800 fps for the fourth case, which is the M93 HVAP-T in an uncut original longer barrel 76-mm gun.

The bow is the thickest part of the Pz IV hull. The 76-mm M62A1 APC with a muzzle velocity of 2600 fps would have no issue defeating the “E” variant at typical combat ranges in the ETO, which were within 890 yd (ref. 7). The turret is more stubborn but is still vulnerable. These results support the reasonable conclusion that the 76-mm gun with the M62A1 APC would have little difficulty defeating earlier model German Panzers. However, by the time the M1A2 76-mm arrived in the ETO in the summer of 1944, the Pz IV received several upgrades in armor and armament. The Germans produced over 3,500 of the Ausführung (Ausf.) H by July 1944 and was the most numerous tank in the Panzer corps during this timeframe (ref. 2). Since the “H” variant was the most numerous tank in the German war machine, it was the probable adversary even after the introduction of the Panther. The armor thickness increased for the bow and side turret over the course of upgrading. Skirt armor strengthened the side of the hull and turret but tended to break off under combat conditions. Table 4 shows the Lambert-Zukas comparison for the M62A1 APC versus Pz IV H.

Table 4 Lambert-Zukas V50 - M62A1 APC versus Pz IV H The effect of the armor upgrade is evident. The V50 is more than doubled for the side and rear strike on the turret, which is the result of add-on armor applied around the turret. The front hull increased to near muzzle velocity for the APC. This was a serious issue since the 76-mm armed with the APC would be marginal at best to penetrate the frontal hull armor of the “H” and was reduced significantly relative to the “E” model on a flank attack as well.

76mm Front Hull Front Turret Side Hull Side Turret Front Hull Front Turret Side Hull Side Turret Lambert-Zukas 2176.41 2667.71 1803.37 1008.87 4176.45 3687.88 2327.01 2075.23 Thompson 1370.41 1681.01 1106.62 702.04 5060.99 2520.26 1338.22 1385.30 BAL 66 1873.00 2244.00 1582.00 987.00 3861.00 3067.00 2528.00 1818.57 M

LAMBERT - ZUKAS (ZERO DEGREE FACING) Gun Caliber 75mm 76mm 76mm 76mm Ammunition M61 APC M62A1 APC M93 HVAP-T M93 HVAP-T (Long Barrel) Muzzle Velocity (fps) 2030 2600 3400 3800 Front Hull 725.00 3078.00 2173.76 3020.75

Front Turret 0.00 1712.00 1239.25 1992.35

Side Hull 1750.00 4170.00 2960.65 3908.00 Side Turret 4050.00 6722.50 5002.00 6400.00 Rear Hull 4050.00 6722.50 5002.00 6400.00 Rear Turret 4050.00 6722.50 5002.00 6400.00 Front Hull 0.00 50.00 163.15 832.00

Front Turret 0.00 1712.00 1239.25 1992.35

Side Hull 1238.00 3622.00 2562.50 3456.39 Side Turret 785.00 3140.00 2217.15 3069.25 Rear Hull 4050.00 6722.50 5001.90 6400.00 Rear Turret 785.00 3140.00 2217.15 3069.25 Front Hull 0.00 0.00 0.00 0.00

Front Turret 0.00 0.00 0.00 249.00

Side Hull 320.00 2653.00 1876.50 2691.00 Side Turret 1000.00 3370.00 2379.63 3250.00 Rear Hull 1385.00 3777.50 2673.95 3582.40 Rear Turret 1000.00 3370.00 2397.63 3

The 75-mm gun is ineffective at point blank even against the front turret of the Pz IV E and is only effective at close ranges against the side hull armor of the Panther. Captain Farmer’s predicament recounted previously in this report becomes painfully clear. The introduction of the 76-mm M1 Gun and M62A1 APC shows a marked performance increase against the Pz IV E in respect to its 75-mm counterpart. The effective range increases from 725 yd to over 3,000 yd against the front hull and from point blank failure against the front turret to 1,700 yd for the 76-mm APC. The velocity drop-off is more drastic with the HVAP-T than APC, evidenced by the nearly 1,000-fps difference in V50 between the two against the frontal armor and a drop-off from 1,712 to 1239 yd, which is in the effective range in table 6. Given most tank engagements in the ETO were within 890 yd, this wasn’t a horrible drop-off in performance (ref. 7). This is not the entire picture of the close-in performance increase with the HVAP-T, which is evident when evaluating the up-armored Pz IV H. The benefit of the HVAP-T round is evidenced in the close range fight. Penetration of the frontal armor of the Pz IV H is increased from 50 yd with the M62A1 APC to 163 yd with the HVAP-T round (table 6). The detrimental effect Pz IV H upgrade on 76-mm APC performance is evident. The front armor was increased and is nearly invulnerable to the M62A1 APC shot. Side hull and turret armor upgrades cut the effective range significantly in flank attack. The performance improvement with the HVAP-T is evident at close range fight. A gun crew needed to know this distinction between their APC and HVAP-T performance to effectively engage the enemy based on range to target. Ramping the M93 HVAP-T muzzle velocity up to 3800 fps to account for the lost cannon length yields some interesting results. The front hull of the Pz IV H would be vulnerable out to 832 yd, covering the full range of tank engagements in the ETO. The Panther is vulnerable at 249 yd, which is improved from the point blank failure. The Hellcat or Sherman armed with the unaltered 76-mm gun would have had a much better chance of defeating the front hull armor of the Panther. Cutting the muzzle length to save weight while reducing velocity on the muzzle exit was a costly mistake that hampered the Tank Destroyer’s primary mission, which was destroying German Panzers. The British had no doctrine imposed limits dictating cannon weight. They incorporated their own 76-mm gun, dubbed the 17 pounder. Three times the amount of propellant coupled with a longer barrel than the US M1 76-mm meant that the muzzle velocity obtained by their Sherman tank mounted weapon was significantly higher than their American counterparts. The armor piercing discarding sabot (APDS) round for the 17 pounder had a muzzle velocity of 3950 fps. Without conducting an analysis for the 17-pounder ammunition, a “what if” scenario can be conducted with the M93 HVAP-T design. Ramping up the M93 to the 3950 fps results in a weapon capable of defeating all German armor at ranges well beyond the average tank engagement in the ETO. Given the 17 pounder was mounted on the same Sherman tank chassis as the M1 76-mm, this is an entirely plausible and effective solution to the Panzer upgrade problem.

I could go on but I think I have made my point. I did some serious research to get the data. If you care to refute it then bring your proof and we can have a discussion about it. Otherwise please remove all references to dubious. So, perhaps you will understand that I provided a gold standard reference and you chose to put dubious get a better article. Honestly do you have a single clue of what you are talking about? Tirronan (talk) 06:52, 24 August 2021 (UTC)

Armour-Piercing Capped (APC), US M62 vs Armour-Piercing Capped Ballistic Capped (APCBC)

The M62 was APCBC, it's just that the US didn't usually refer to the shell with the whole acronym. It's likely these two shells mentioned in the first Performance table are the same shell. Performance appears to be identical as well. MaxRavenclaw (talk) 20:09, 25 December 2022 (UTC)

I believe the same happened with the HVAP ammo. Three instances of the same ammo just named differently in different sources. The T4 and the M93 are essentially the same rounds. Or at least very similar, and it would be worth taking a close look at the sources. It is possible the sources might differentiate between the original T4 and the T4E20, standardised early in 1945 as the M93 (Constance McLaughlin Green, Harry C. Thomson, Peter C. Roots – The Ordnance Department Planning Munitions for War (1955, Center of Military Histoy US Army) p. 373). — Preceding unsigned comment added by MaxRavenclaw (talk • contribs) 20:40, 25 December 2022 (UTC)

The whole table is a mess. Hunnicutt uses yards not meters. I'll try to tidy it up. MaxRavenclaw (talk) 20:57, 25 December 2022 (UTC)

Bovington used yards too. I've compiled the values from Bovington and Hunnicutt in one table and the ones from Zaloga, which does use meters, in another table. I've removed Woodman since I couldn't verify the source and no page was provided, but it did seem to just repeat the values from Bovington and Hunnicutt. Feel free to add the source back if you can check the page and confirm. MaxRavenclaw (talk) 21:31, 25 December 2022 (UTC)