Did some quick testing with the 17lber (needs fixing)

Game Discussion Simulator Battle
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Yep, I’m moaning about Britain being handcuffed again.

I think most people would agree that there’s something not quite right about the 17lber. Its damage is unreliable at best with at times the round struggling to penetrate tanks it was literally designed to (and did) destroy. At almost point blank range it will reliable bounce off of a Jagdpanzer’s UFP and sometimes the round goes wherever it wants for no reason whatsoever. An incredibly frustrating and unfair mechanic considering it’s forced to aim for weak spots on tanks such as the Panther… well that’s if the game decides to let it penetrate even if the round hits said weak spot. This goes for the Tiger too.

Here’s some quick clips to show the lack of damage and ludicrous ways it can bounce or just straight up not penetrate. These were quickly thrown together so apologies for the rough editing.

Yes, you just saw it bounce clean off of a truck window, an Ostwind’s turret and three shots going straight into the side of a Tiger with the shrapnel clearly smashing into one of the crew for absolutely minimal effect, or no effect at all with the first shot (the black crew was caused by another tank).

Now for accuracy. All 3 tanks tested at the same range (Firefly, T-34-85, Panther D) and as predicted the Firefly is awful compared to the other two with its spread being almost the size of the Panther’s entire UFP. The other two which barely even need accuracy due to the broken nature of APHE are practically pixel perfect. The funny thing is off memory I haven’t even spaded the T-34-85.

You aren’t missing in the Firefly because you made an error, you’re missing because the game decided you should miss, at which point you’ll be instantly deleted by whatever tank you’re facing which has APHE. Not only is this completely unhistorical but you can’t even argue it’s fair from a gameplay perspective.

It seems to me like it’s mainly only British guns that are massively affected by crap accuracy. APDS rounds fired by the Centurions and Conqueror are wildly inaccurate along with massively underperforming with the “shell shattering” mechanic.

Here’s a Conqueror shooting at a Ferdinand. After the first shot where I adjust my aim watch how the shell shatters, the 400mm+ pen round stops at the driver and how the gun is so inaccurate that the round can almost completely miss the tank! If that were a T-54 that round would’ve smashed into the ground next to it.

For the love of the snail please fix Britain. If you’re not going to drastically, historically and realistically nerf APHE then there’s zero excuse for British guns to be this terrible. Especially when historically the 17lber was known for being an accurate gun (Britain doesn’t get the APDS while Italy does, wonder why?) and the Conqueror was literally designed to sit at the rear and snipe enemy tanks at range.

As it stands the Conqueror is the one getting sniped. Hilarious isn’t it?

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About the non-penetrations: this isn’t 17 pounder exclusive, any cannon can non-pen even when it should’ve penetrated. Bugs happen.
Also on the first video you aren’t hit by APHE at 0:54, Hl.Gr 39 is a HEAT round, and the explosion managed to penetrate the Avenger’s very weak side armor and damage an internal component, which triggers overpressure.

On damage, yes, the 17 pounder should deal more reliable damage, but again, this isn’t 17 pounder exclusive, a lot of different AP rounds apply. For example, US cannons start with solid shot AP rounds when stock, and those rounds are horrible, they have poor penetration and very poor damage.

About accuracy: the Panther’s 75 mm KwK42 and the T-34’s 85 mm D-5T are more accurate than the 17 pounder because they were actually bug reported with real life documentation.

Bug report for German 75 mm L70 cannons: Community Bug Reporting System
Bug report for Soviet 85 mm cannons: Community Bug Reporting System

These cannons used to be just as inaccurate as the 17 pounder is. It’s just that there’s actual documentation showing that they should be more accurate than that, and these bug reports got implemented. And the same applies to the US 76 mm and 90 mm cannons. Both of these used to be just as inaccurate as the 17 pounder, but the accuracy got bug reported and they became more accurate as a result.

Also:

As far I can tell, this is just not true. The inaccuracy of the 17 pounder is one of the reasons why the US never adopted it, as during US testing the 17 pounder always came up to be less accurate than the 76 mm or 90 mm cannons, specially with APDS, a round that, as the US saw it, was the only one that provided a meaningful advantage in penetration. The 17 pounder APDS was so horribly inaccurate that on one test (which they were specifically testing the dispersion of rounds) they actually just gave up on testing the 17 pounder APDS because they couldn’t get the round to even hit the target.

Now, some people state that the 17 pounder was actually accurate but came out to be inaccurate in accuracy testing because the sheer flash and smoke of the cannon firing made it difficult for the gunner to adjust his aim as he wouldn’t see where the round landed. Some also say that only the early APDS was inaccurate because of problems with the sabot detaching which were fixed later. However, this doesn’t matter, what matters is documentation showing actual accuracy/dispersion values that show the cannon to be more accurate than it has been made out to be, which is something I’ve yet to see. However, I’ve seen testing commenting on the 17 pounder’s inaccuracy multiple times.

If you want the 17 pounder’s accuracy to change, do the same thing that people did to make the Panther’s, T-34-85’s, M4’s and M26’s cannon to be more accurate: bug report it with relevant documents and in game testing that shows the accuracy to be worse in game than what is stated in said documents.

This also applies to the Centurion and Conqueror examples you mentioned.

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I don’t think it’s just a bug with the 17lber, I’ve played for other nations and you’re correct regarding random buggy bounces but they happen with shocking consistency with the 17lber. I’d be willing to wager that I’ve had far less bounces with almost any other gun than the 17lber. British APDS (when it doesn’t BS shatter) when it can actually hit usually penetrates as you’d expect. The 17lber will reliably bounce on the side of a Tiger turret and as mentioned the Panther turret to go with it.

Overpressure is a broken mechanic if that’s the case. The round struck the engine bay, barely damaging the engine and yet somehow killed the crew? Then there’s the second clip which is indefensible.

Only the APDS round was inaccurate and the muzzle flash affected follow up shots, not necessarily the accuracy itself. In regards to it’s actual accuracy during Russian testing it was declared more accurate than the Russian 76mm gun and this was without an actual glass sight. To quote the Russians:

“The penetration, stability, and precision of the 17-pdr gun made it a powerful anti-tank gun that matches modern requirements.” The vast amount of online information I can find about the 17lber inaccuracy is regarding the APDS. Not the AP.

I’ll see if I can get a bug report sorted out as it desperately needs fixing. British tanks are fighting an incredibly uphill battle compared to most other nations.

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I addressed both of these statements right afterwards.

Also, when I say that it was “not true”, I mean purely the part of the 17 pounder historically being known as an accurate gun. That isn’t inherently about if it was or wasn’t actually accurate, more on how it was known. The accuracy of the 17 pounder is right now a fairly debated thing, precisely because of contradicting evidence, some saying it was less accurate than contemporary cannons (basically any US report where the 17 pounder was tested), and some saying it was accurate (like the Russian report you’re talking about).

I will say this though, the Russian source by itself means little. In US testing, while the 17 pounder was less accurate than the 76 mm and 90 mm with normal AP rounds, it still was accurate enough to hit a target, which in a lot of cases is what matters. For the Russians, they don’t provide any numbers on the actual precision of the cannon, and it’s completely possible that the cannon is stated to be precise simply because it’s accurate enough.

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Also, while yes, a majority of reports on inaccuracy come from the APDS, there are still US reports that state that even the normal AP rounds were less accurate than the AP rounds fired from 76 or 90 mm cannons.

The Chieftain has a very good 3 part blog that goes over such a report, where the US compares an M4A3 Firefly (yes, an M4A3 modified to have a Firefly turret just for this test), an M4 76 and an M26 to sort of see which cannon set up was most desirable.

Part 1 of that blog (seen here) contains the part of the report that goes over the dispersion obtained from each tank, including the whole bit I mentioned where they gave up on testing the APDS round.

And again, the AP rounds came up overall worse than the 76 mm and 90 mm cannons. They came to a maximum overall dispersion of 7.38 milliradians horizontally and 7.58 vertically, which is 0.423 and 0.434 degrees respectively. This is actually lower than the ingame value as far as I can tell, but still higher than the Panther, T-34-85, etc.

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There was inherent bias in the US trials. You should be using British, Australian, or Canadian tests.

I’ve got some dispersion charts somewhere. Wildly different than US claims.

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Any luck finding the dispersion charts?

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No the 17pdr was inaccurate when mounted to the Firefly and using the APDS rounds that said they could still reliably hit 500 yard targets. The standard AP round was far more accurate most tank engagements were at 400m to 800m.

Gaijin have added an arbritrary figure for the 17pdr APDS years ago as a “balancing” tool since then they have also nerfed the penetration added volumetric amour to some tanks and made the round far less reliable to the point even point blank straight on it may not penetrate a Tiger. Yet the KV2 can lob an HE shell 1300m and hit the mark it is aiming for…Balance

The US adopted the 76mm because they had inferior testing methods and didnt want to mount a British gun.
US tested the 76mm on US made steel and not German equivalence which meant when they thought they should on paper be able to penetrate a Panther at 800m they couldnt. Despite the tests saying they should be able to. Which is why they rushed to have the 90mm gun fitted to the M36…If the 76 is so good why fit your Tank destroyers with a 90mm gun…

The 17 pdr was tested against German steel (or steel to that level of hardness) Which is why Britain offered the 17pdr as a way to defeat German armour.

And was proved in WW2 and after it was one of the best AT guns ever produced

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Ah yes the classic british fanboy.
In what way? Coming late? Beeing quite heavy for the size? Average performance for the size? There is a reason many went with 90mm guns.

Edit: point still stands.

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90mm didn’t even show up until late war

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Many went with 90mm guns for what reason?
Raw AP penetration?
No because of the change to CE projectiles… US sold tanks with the 90mm gun.

Not a fan boy it’s just a known fact the 17pdr was respected by all including the Germans who faced it.
It saw use after WW2 and was also very capable.

It was replaced by the 20pdr and that development lead to the most important gun of the cold war era the British L7 105mm

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From “The Chieftain’s Hatch: US Firefly Pt. 1”:

Spoiler

This successfully completed, they went back to the 500 yard target and fired SVDS.*

Results were rated “poor”, with 8 rounds on target, and two sensed as being about 36” below the panel, but for the purposes of calculation they were presumed to have the same average deflection as the 8 rounds that were on target. Overall deflection was 2.35mil, 4.34mil elevation, with means of 0.5mil and 0.92mil respectively.

Then they tried at 1,000 yards. After firing 18 rounds trying to register, (Successive rounds with the same sight picture were observed as over, left, short) they decided to abandon further testing of the round except for armour penetration.

*Refers to testing APCBC at 500 and 1000 yards.
Back to 17 pounder APCBC.

So, the average at all ranges was calculated to be 7.38mil/7.58mil overall, and means of .189mil and .205mil. The testing complete, they then dug into the records to find the test results of 90mm and 76mm guns.

Mean dispersions for deflection and elevation were .115mil/.142mil for the 90mm and .112 and .110 for the 76mm respectively.

Now I never said that the 17 pounder AP had horrible accuracy and couldn’t hit anything compared to the 76 mm or 90 mm cannons. However I did state that it was less accurate, which as far as I can tell is factual. I also stated that specifically the APDS was far more inaccurate, and that they had given up on testing the dispersion of the APDS, which both statement are backed up by what I linked.
I also stated that the APDS round was what provided a meaningful penetration advantage to the 17 pounder, which from everything I’ve gathered, is true. That’s not to say that the 17 pounder AP didn’t have more penetration than the 76, because it did, it simply still wasn’t enough to reliably go through the front glacis of something like the Panther, only the APDS did that.

The US results show 8 APDS hits out of 10 rounds fired on the 1.8 by 1.8 meter canvas at 450 meters, with shots that did hit having wildly different dispersions.
However there is another test, conducted in Isigny, France, where they fired 17 pounder and 76 mm projectiles at actual Panthers, which is also talked about in a blog post done by the Chieftain (“The Chieftain’s Hatch: US Guns, German Armour, Pt 1”). In this test, at ranges of 180-550 meters, out of 42 APDS rounds fired from the 17 pounder, only 24 hit. The British state that the lot had not been proof fired and was of sub-par quality, but these are the results we have.

I don’t get what you mean.

As I said, accuracy was one of the reasons. There’s plenty others, bias from the US being one of them.

And their tests of the 76 mm never said that they could penetrate the Panther, that was just a really stupid assumption they made. They assumed that, because the 76 mm penetrated 100 mm at 30 degrees on one test, it would penetrate 80 mm at 55 degrees, which is just insanely stupid. Even US penetration graphs against US steel show that the 76 mm was not up to that task. For example, take “Terminal Ballistics Data, Volume III”, which is from September 1945:

Spoiler

TBDV3, M62
TBDV3, M621343×904 294 KB

Dashed lines indicate estimated penetration values.

In other words, they never actually even tried to simulate a Panther, they shot against completely different plates and made an assumption. That’s not to say that US steel wasn’t softer than German steel, it was, but it just didn’t matter for this assumption. When they actually wanted to see if they could penetrate a Panther, they tested against Panthers, like how they did with the 90 mm ammunition which had been purposefuly made to be used against Panthers.

Also I never said that the 76 mm was a fantastic gun, or even a good gun. I compared the 17 pounder’s accuracy with guns like the 76 mm and 90 mm, and mentioned how accuracy was one of the reasons the 17 pounder wasn’t adopted by the US, in response to @dannaryan stating that “historically the 17lber was known for being an accurate gun”, when all the results I’ve personally seen show that while the 17 pounder could hit targets (assuming it was firing AP), it was definitely less accurate than other guns.
I even said this:

If you want the 17 pounder’s accuracy to change, do the same thing that people did to make the Panther’s, T-34-85’s, M4’s and M26’s cannon to be more accurate: bug report it with relevant documents and in game testing that shows the accuracy to be worse in game than what is stated in said documents.

This also applies to the Centurion and Conqueror examples you mentioned.

In the end it doesn’t really matter what the US did and didn’t do. The whole point is that the 17 pounder wasn’t as accurate as other cannons, even if by itself it was accurate enough to hit the target it was shooting at, at least with normal AP rounds.

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Gaijin have a dispersion modifier set higher for the likes of the 17pdr

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Ah, yes, it does.

It’s 0.075 degrees of maximum vertical and horizontal dispersion, while cannons like the 75 mm KwK 42, 88 mm KwK 43, 90 mm M3, 76 mm M1 and 85 mm D-5T have 0.027.

But again, they only do so because they were bug reported to be more accurate. You can find the bug reports if you search for them (for example, the one for the US 76 mm cannon: Community Bug Reporting System). Before these guns were bug reported, they all had similar dispersion values.

One thing to mention is that these 0.075 degrees apply to all rounds fired by the 17 pounder, from the HE, to the APCBC, to the APDS. The APDS has multiple tests conducted during the war that show attrocious accuracy, much worse than the 0.075 degrees shown in game, and the AP shot shows itself to have slightly better overall accuracy than those 0.075 degrees (although not by much).

Personally, I bought the A.C.IV when it got on sale, and roughly at the same time I spaded the Italian Fireflies. I’ve found that the 17 pounder was accurate enough to hit a target at pretty much any range: not really accurate to hit weakspots, but that matters less given the power of the gun.

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This wasn’t done as a mark of realism, many guns as I mentioned are more accurate than they have any right to be. I mentioned the KV2 being able to shoot massive HE shells long distances and accurately.

This was done because in Gaijins eyes the APDS round was overperforming. It was upsetting the balance, German players and Russian players didn’t like their armoured tanks being destroyed and by British tanks no less. we saw the exact same cycle with the mistreatment of HESH.

Now the data shows that “SV Shot Mk1” was an inaccurate round. However the game doesn’t take ammo type into account when calculating dispersion (or at least I don’t think it does?)

To get round this they just applied a blanket nerf on all 17pdr and their accuracy.
As you move into 5.3 and 6.0 weakspots are a must.

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That is not the case. The 17 pounder just continues to use what is effectively a default value for these late war guns.

I know this because these were the dispersion values for all these guns until they got their dispersions buffed with bug reports:

  • 76 mm M1 and M7: 0.075 degrees
  • 90 mm M3: 0.065 degrees
  • 75 mm KwK42: 0.07 degrees
  • 88 mm KwK36: 0.065 degrees
  • 88 mm KwK43: 0.06 degrees
  • 85 mm D-5T and ZIS-S-53: 0.075 degrees
  • 122 mm D-25T: 0.065 degrees

And right now all these guns are 0.027 degrees solely because people bothered to test the accuracy and bug report it.

There’s a clear pattern: the bigger and larger the gun, the more accurate it is. These values go back to at least 5 years, it’s impossible to know if they go back further since 5 years ago is when this stuff started being catalogued with the datamine github.

Fact is, they didn’t nerf the 17 pounder’s accuracy. Its lack of accuracy in comparison to other guns is a result of those other guns being buffed while the 17 pounder has been left in a “default” state.

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Actually there is already a report on the 17 pdr.
https://community.gaijin.net/issues/p/warthunder/i/mPF3z4eJorXD

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It will probably be fixed sometime soon then.

Although probably not to the level that report says. That report is using the mean, or in other words, expected dispersion value, when WarThunder stores an absolute maximum.