Fireflies Inaccurate?

[civdiv]

I'm currently reading 'No Holding Back, Operation Totalize, Normandy, August 1944' by Brian A. Reid. Great read BTW; very detailed and written from both the operational level and down to the nitty-gritty of tactical combat. It also goes into the build-up of the Canadian Army in WWII, it's organization, training, and personalities. Definately a highly recommended book.

Anyways, on page 155 of the hardcover 2005 Robin Brass Studio edition is a photo of two Sherman tanks, one of which is a Firefly. The caption reads; 'Allied armour at dawn The tank on the right can be identified as a Sherman Firefly armed with a 17-pounder gun. While this gun could kill any German tank, it was inaccurate and a hit at over 1,000 yards was a matter of luck. (NAC/PA 162391).'

Anybody know anything about this innacuracy, I have never heard the Firefly was inaccurate. Is this an optics issue (That is pure guess on my part). IIRC, British optics were considered below US standards, which were similarly below German standards, while Soviet optics were the worst of any of the major powers.

Anybody know anything about Fireflies being inaccurate?

Is my laydown of WWII optics accurate?

civdiv

[gibsonm]

I suspect (no facts or references to back it up though) that it might be to do with the flight characteristics of the 17Pdr APDS round.

[JonS]

... and more specifically to do with petal separation issues with that round.

(edit: Fantastic book, BTW. The author has posted here)

[gibsonm]

“Petal”? surely that would make it APDP?

Must have been a heap of fun designing the driving bands and sabots so they worked properly (all the while the guys at the front are screaming for something more effective).

[John Kettler]

civdiv,

This issue has been discussed before and is, I believe, modeled in the game as well. JonS is spot on as to the why of the lack of long range accuracy.

The British pioneered the APDS round, and clean separation of the sabot elements or petals from the penetrator had and has everything to do with long range gunnery, in that a small yaw in close that wasn't factored into the firing solution became/becomes a big miss at longer ranges.

Regards,

John Kettler

[Redwolf]

No, in addition to the problems with ADPS there were some other issues with the 17pdr's accuracy. The details escape me right now.

[MikeyD]

Sabot rounds (discarding and otherwise) were a headache all the way up through the M48 MBT's gun in the 60s-70s. From what i've read its not that they're 'inaccurate', as in wide dispersion pattern but that they're 'erratic' as in occasionally flying off in odd directions for no apparent reason! Seems to have something to do with how cleanly the sabot separates from the round in flight. Add to that barrel whip from the thin-walled long-tube high pressure gun and inaccuracy problems will start to mount.

I think I read modern gun barrels are 'cured' somehow with high pressure hot oil in an effort to minimize barrel flexing... I think

[Sirocco]

There's a comment in Baverstock's Breaking the panzers about a common crew aiming error with the towed 17pdr. I can't recall the exact quote.

[flamingknives]

Originally posted by gibsonm:

“Petal”? surely that would make it APDP?

Must have been a heap of fun designing the driving bands and sabots so they worked properly (all the while the guys at the front are screaming for something more effective).

Petals are elements of Sabots as the usage relates to APDS, you ignorant tankie

I don't recall whether 17pdr APDS has a single shoe or multiple petals.

Designing it so it works on a lovingly-crafted one-off probably isn't too hard. Designing it so that it can be made to sufficient quality on a repeatable basis is the tricky bit.