Hit Percentages with Bracketing: 75L48 and 75L70

[rexford]

After setting up a bracketing program on my computer, the following results were obtained for 75L48 and 75L70 APCBC against the front of a stationary T34 M43:

21 Guns Firing at 21 T34, Gun Stops Firing After a Hit

Program Stops At End of Fourth Round Attempts

Assumes Excellent Guns with Low Dispersion

1250m

=====

75L48

1- 4 of 21 shots hit (19%)

2- 5 of 17 hit (29%)

3- 8 of 12 hit (67%)

4- 4 of 4 hit (100%)

21 of 21 hit

75L70

1- 6 of 21 hit (29%)

2- 8 of 15 hit (53%)

3- 5 of 7 hit (71%)

4- 2 of 2 hit (100%)

21 of 21 hit

1500m

=====

75L48

1- 3 of 21 hit (14%)

2- 4 of 18 hit (22%)

3- 7 of 14 hit (50%)

4- 4 of 7 hit (57%)

18 of 21 hit

75L70

1- 4 of 21 hit (19%)

2- 6 of 17 hit (35%)

3- 6 of 11 hit (55%)

4- 3 of 5 hit (60%)

19 of 21 hit

2000m

=====

75L48

1- 2 of 21 hit (10%)

2- 3 of 19 hit (16%)

3- 4 of 16 hit (25%)

4- 6 of 12 hit (50%)

15 of 21 hit

75L70

1- 3 of 21 hit (14%)

2- 4 of 18 hit (22%)

3- 5 of 14 hit (36%)

4- 6 of 9 hit (67%)

18 of 21 hit

The initial range estimates had an average error of 20% from the actual range and followed a bell shaped normal distribution, from 0% error to +/- 49%.

The Germans required that crews be able to hit a target at 1200m-2000m by the fourth round at the completion of their training, which appears to be possible in most cases. If the initial range estimates were less than 20% in error on average the 75L48 would probably make it (+/- 200m would do it, which is extremely good estimating for 2000m targets and was not considered reasonable).

[Mr. Tittles]

Perhaps you should do a run for the 88mmL56 flak gun with both types of AP?

The 88mm Flak guns did have a means of measuring ranges to less than the +/-200m presented here. The rather large rangefinder was part of the kit of this unit (actually most flak had some type of rangefinders).

[rexford]

Originally posted by Mr. Tittles:

Perhaps you should do a run for the 88mmL56 flak gun with both types of AP?

The 88mm Flak guns did have a means of measuring ranges to less than the +/-200m presented here. The rather large rangefinder was part of the kit of this unit (actually most flak had some type of rangefinders).

Good suggestion.

I believe that there is a combat report in Jentz' Dreaded Threat where a group of 88mm Flak guns took on a pack of T34, and it took about 12 shots per tank kill. Didn't sound like the 88's were too successful in getting hits that day.

[Mr. Tittles]

My main thought would be that that while the earlier 88mm AP rounds may not have had the accuracy of the later Tiger I 88mm rounds, they may have made up for it with very accurate range/heading readings and vast amounts of rapid fire.

[rexford]

Mr. Tittles,

Just wanted to say that much of my recent research, including the home experiments with triangles, was a result of the questions you've raised on the various threads. You ask good and difficult to respond to questions, and your efforts are appreciated.

Lorrin

[rexford]

Originally posted by Mr. Tittles:

My main thought would be that that while the earlier 88mm AP rounds may not have had the accuracy of the later Tiger I 88mm rounds, they may have made up for it with very accurate range/heading readings and vast amounts of rapid fire.

Although the dispersion data for the Flak 88mm Pzgr shows a marked inferiority to the Tiger Pzgr 39. Rate of fire would be an important factor, as you note.