Bofors AA guns in A/Tk role

[David W]

Actually, does anyone know the weight of the standard 40mm Bofors AA round, and how much of that was explosive filler?
I can only find figures for the two pounder.

[Urmel]

Depends on the country?

http://www.navweaps.com/Weapons/WNUS_4cm-56_mk12.htm

Around 900g for the round. AP had no HE filler, US rounds had 67g of HE filler. Projectile weights seem to have been fairly identical.

[David W]

Thanks urmel.

It would seem from the figures that I have uncovered that the bofors AP round was slightly less effectve than the 2 pdr.

[Juha Tompuri]

It would seem from the figures that I have uncovered that the bofors AP round was slightly less effectve than the 2 pdr.

Is the question about the 2 pdr AT or AA gun?

Regards, Juha

[Clive Mortimore]

Hogg gives the 2 pdr and Bofors both 42mm penetration at 1000 yards.

[David W]

Juha.

we are comparing the 2pdr A/T solid shot to the 40mm Bofors A/A firing the A/T round available to the Commonwealth in 1942.

[Juha Tompuri]

A-ha, thanks.

Well, the 2 pdr AT gun ammo had slightly more muzzle energy (a bit less speed, but heavier shot) and so also more energy at the target AFAIK.
http://www.quarry.nildram.co.uk/37-40mm.htm

Regards, Juha

[Urmel]

Hi all,

Confirmation that British Bofors guns were issued with AP rounds in late 1941, at least, and that both Hy. A.A. and L.A.A. units were expected to take part in the ground battle if tanks came within effective range is found in the following extract from "Standing Operational Orders for Hy. and L.A.A. defences of L.G 75 and 76" issued on 9 December 1941 by 88th Hy. A.A. Regt:

Hostile Tanks.
24 rounds A.P. ammunition will be kept at all L.A.A. gun sites in a separate box distinctively marked.

When within effective range, both Hy. And L.A.A guns will engage enemy tanks in preference to E/A. The effective range for 3.7” A.A. guns against tanks is 1,000 yards and of Bofors guns 400 yards.

Source: WO169/1582 - W.D. 88th HAA Regt RA.

Regards

Tom

Missed this one, thanks for that.

Not very good instructions. At these ranges, the guns would have been taken apart by the tanks long before.

Both L.G.s were frontline L.G.s

[phylo_roadking]

Not very good instructions. At these ranges, the guns would have been taken apart by the tanks long before.

And be seen to be fired upon - surely they had quite a high profile?

[Urmel]

Well one would hope they were dug in, being stationary airfield defense and all that.

[phylo_roadking]

Maybe revetted around would be ok...



...but dug in for AA defence, there's a problem with depression for a/t work...

[gambadier]

If the first photo is where I think it is (Townsville, N QLD) then tanks would be fairly high on the unlikely list.

[phylo_roadking]

Probably! But I was illustrating the compromise to be struck between the relatiively high profile....and being able to depress to the horizontal for A/T work

[John T]

Probably! But I was illustrating the compromise to be struck between the relatiively high profile....and being able to depress to the horizontal for A/T work

Using the Swedish mount the gun had an elevation of -5 to +90 degrees.
and the minimum gun height above ground where 1085 milimeters for the wheeled mount and 833 milimeters for the fixed mount.

source the maintenance manual from 1943.


And to state the obvious when comparing with the 2 pounder, the Bofor's rate of fire where higher.

Cheer
/John

[Urmel]

Probably! But I was illustrating the compromise to be struck between the relatiively high profile....and being able to depress to the horizontal for A/T work

Still beats having to fire from the back of a truck in the open. Shrug.