Destroying a Myth: the 17 Pounder AT Gun

Yes, it's performance is a myth. And here's why.

Raw penetration:

17 Pdr:


Long 88 and Panther gun:


90mm M3 found on Pershing and M36:


Observations:

The 17 pdr is the best British AT gun fielded during the war, yet the the British cutting edge has:

- Only 3mm pen advantage over the earlier KwK 42 at 100m when comparing full bore ballistic capped AP rounds (apples to apples)

- APDS on the 17 pdr is better than the APCR on the L/70. We will get into why this round in particular is utterly useless in a bit though.

- The KwK 43 completely crushes the 17 pdr in APCBC performance.

- vs. armor below 30 degrees in slope the KwK 43 completely crushes the 17 pdr APDS in penetration performance.

- The regular 90mm has similar APCBC performance to the 17 pdr.

- Higher APCR pen over 17 pdr APDS but with worse performance vs. sloped armour.

- Long 90 found on Super Pershing is superior.

- Soviet D-10 (which I didn't list) has similar APCBC performance to the KwK 43, but loses pen a bit faster over distance. This gun crushes the 17 pdr APCBC as well.

So as you can see, the penetration performance of the 17 pdr is not even close to good by German standards, and we didn't even compare it to the best gun of the war, 128mm KwK 44.

Source: https://www.scribd.com/doc/219173969/WWII-Ballistics-Armor-and-Gunnery

But here is the real joke of it all. The 17 pdr's accuracy (this goes for the Comet's gun as well as it is a shortened 17 pdr).

At 1000 yards, the 17 pdr has a 14% chance to hit a target 5' wide by 2' high (Panther turret size basically) with APDS. At 800 yards (around avg. engagement distance in Western Front) it has a 21% chance.
1 in 5 shots from APDS slinging 17 pounder has a chance of even hitting a hull down Panther. This means a Panther could get in up to 4-5 shots on average on the Firefly before it is even struck. Lol. The APC fares a bit better, but is still really bad. 52% chance at 1000m. This trash accuracy (coupled with some other issues like garbage HE shell) is why the U.S did not adopt the 17 pdr over their 76mm M1. Keep in mind the average ammo load for a firefly was 6% APDS out of all it's rounds.

At longer ranges the APC shell had no chance of penning a Panther, and with APDS, no chance of hitting it. Vs. A Tiger II, it has no chance of penning it's turret because it can't hit it with APDS. Vs. a Jagdtiger, no chance. Vs. smaller targets like StuG and Jagdpanzer IV, even APCBC will have trouble hitting at far range.

Source: http://www.panzer-war.com/page40.html

Like most British armoured tech of the war, the 17 pdr is a underwhelming but has a legendary reputation from non stop propaganda and fanboys. It was a good gun by British standards, a meh gun by American Standards, a bad gun by Soviet standards, and an utterly worthless gun by German standards.

Taken from a holistic perspective of the war perhaps, but you have to bear in mind the anachronistic argument you're making. It was conceived in 1942! Of course technology during war time had advanced, at the time it was considered a god send compared to the QF 6and 2 pdrs and one would hope it would naturally be out classed by kit from '44 onward, yet it was still effective enough to warrant production.

Nice breakdown OP!
Stellar post for first post too!

One thing tho, when you compare yards to metres, I want to stab you through the screen.

And yes, the 17 pndr was retrofitted with AT rounds late war, and on the Fireflys produced such a big flash, that the gunner and commander had to blink when firing.

Same british propaganda which made the french looks like coward when they sacrified their first army at dunkirk to save the birtish Expeditionnary corp

http://www.telegraph.co.uk/news/obituaries/9114158/Joe-Ekins.html

this is obviously allied lies

No 17pdr could hit a barn door at 1,000 yards according to OP's single source, let alone a smaller PIV at 1,200 yards with a single shot

To turbotortoise, the rounds I used for comparison were fielded in 1944 on the 17pdr. If I were to compare the 17 pdr ammo that was contemporary to the KwK 42's 1943 AFV debut, the KwK would have come out on top vs. the earlier AP rounds the 17 pdr had. The 17 pdr was only effective enough to warrant production because the Brits had literally nothing else. This is why the 20 pdr was built (but this gun could not pierce the hull of it's contemporary opponent, T-54, beyond very short distances. This is why the L7 was mounted on Centurions in 1959).

And wow, 4 WHOLE Tigers were ambushed in the area of operations that saw the shortest range tank engagements of the war? 17 pdr OP! Cute, but data is data.

Same british propaganda which made the french looks like coward when they sacrified their first army at dunkirk to save the birtish Expeditionnary corp

Watch WW2 in Color. The British narrator mentions their sacrifice at the beginning of the series.