ATG evolution

[Vincenzo]

ATG, evolution, towed
first combat

British
2 pdr, weight 838 kg, pre war
6 pdr, weight 1143 kg, may '42
17 pdr, weight 2101 kg, february '43

United States
37 mm, weight 414 kg, december '41
57 mm, weight 1143 kg, july '43 ?
76 mm, weight 2210 kg, november '43 ?

Soviet
37 mm, (spain war) '37
45 mm, (spain war) '37
45mm longer, '43 ?
57 mm,weight 1800 kg, december '41
100 mm, '45 ?

soviets used 76 and 107 mm field guns and 85 mm AA guns in AT unit it's hard find their first combat (imho from late '41 to '42)

German (take not squeeze-bore and low pressure)
37 mm, weight 440 kg, (spain war) '37
47 mm (t), may '40
50 mm, weight 1062 kg, april '41
75 mm (f), weight 1270 kg, summer '42?
75 mm, weight 1500 kg, april '42 ?
76 mm (r), weight 1760 kg, spring '42
88 mm, weight 4750 kg, mid '43 ?
128 mm, '45 ?