German Use of Battlesight Aim

[lorrin]

A German report dated February 4, 1944, from Panzerjagerabteilung 14, details the use of a battlesight aim procedure for 75mm Pak 40 guns (the procedure is not called battlesight aim).

Various examples in the report show how aiming at a longer range than the target is estimated to be at will allow hits against targets within a range spread where the width of the spread decreases as the range increases.

If the gun aims for the bottom of a 2m tall target with a range setting of 1200m and using Pzgr 40 ammunition, hits will be scored on all such targets between 855m and 1200m, which allows continuous accurate fire without changing the gun range setting.

The report indicates that gun crew commanders keep a table of range settings with them for use in the field, and the table settings are as follows (the German ballistic table results for 75mm Kwk 40 and Pak 40 are in brackets, for comparative purposes):

75mm Pak 40 Pzgr 39

=====================

0-200m (0-200)

0-400m (0-400)

0-600m (0-600)

0-800m (0-800)

620-1000m (750-1000)*

1020-1200m (1020-1200)

1240-1400m (1260-1400)

1360-1500m (1375-1500)

Notes:

1. If a group of 2m tall targets, or single 2m tall tank, is at 1020m to 1200m range, a gun range setting of 1200m will result in a hit.

2. *-for 750 m/s muzzle velocity, our calculations show that setting gun to 1000m range and aiming at target bottom will overfly 2m tall target at 620 by about half a meter but will just hit the top of a 2m tall target at 750m. Report table appears to contain an error for this range.

75mm Pak 40 Pzgr 40

====================

0-200m (0-200)

0-400m (0-400)

0-600m (0-600)

0-800m (0-800)

0-1000m (0-1000)

855-1200m (930-1200)

1165-1400m (1205-1400)

1300-1500m (1330-1500)

75mm Pak 40 Pzgr 38 Hl/B

========================

0-200m

0-400m

455-600m

715-800m

980-1000m

1155-1200m

1365-1400m

1470-1500m

The report ranges do not consider the impact of random shot to shot dispersion or scatter, which may result in some misses within the listed range intervals (locations where the trajectory is near the top or bottom of the target and scatter may move the flight path off the target).

[ September 24, 2004, 04:31 AM: Message edited by: lorrin ]

[Mr. Tittles]

This is what I thought they were doing also. Notice the 'forgiveness' in ascertaining range with precision.

The Germans criteria for passing gunner's school did not place any testing at stationary targets at less than 1000m range. I think the reason is that there was enough technology to determine ranges to a acceptable precision, and the guns performance using that range precision allowed forgiveness within a certain 'band'.

[lorrin]

Abovementioned report provided by Miles Krogfus after discussions on German aiming methods.

[Mr. Tittles]

75mm Pak 40 Pzgr 39

=====================

0-200m (0-200)

0-400m (0-400)

0-600m (0-600)

0-800m (0-800)

620-1000m (750-1000)*

1020-1200m (1020-1200)

1240-1400m (1260-1400)

1360-1500m (1375-1500)

This data shows that using a true battlesight technique was not preferable. It would lead to hits along the very top or bottom (or misses) when better results could be obtained. Notice that hits could be achieved at 0-800m (zone 4 lets say), but if the target was truly closer, and could be 'ranged' as such, then one of the closer 'zones (0-200m or 0-400m) would be used. This may be because the Germans were aware of the scatter and the goal of focusing as much probability towards the center of the target mass is being investigated.

Just to be clear, the parenths denote a 75mm KWK firing a 39 (APCBC) projectile? This would seem to indicate that PAK 40 and KWK had different velocities?

[ September 24, 2004, 12:24 PM: Message edited by: Mr. Tittles ]