please, tell me what is the equivalent armor of 120mm at 30°from horizontal plane
It doesnt matter.
If IS-2 has 30° sloped armour and the Penetration data for the panthers main gun is also tested against a steelplate of sloped 30° then it says that the panther can penetrate 174mm of armour at a distance of 500m against a sloped steelplate at 30°(which is exactly what the IS-2 sloped armour is).
30° = 30°
It seems you don t understand that or you don t want to understand it.
You could also ask: please, tell me what is the equivalent Penetration for the panthers main gun of 174mm at 30°from horizontal plane.It doesn t matter.
And the IS-2s main gun was aso not the most accurate since it was a howitzer gun and howitzers tend to be unaccurate.Not to mention the extremely slow rate of fire of 2 shots per Minute of the IS-2, while panthers and tigers could shot 8-9 shots per Minute and the guns where much better accurate.
I m sorry to say but IS-2 wasn t the wonder tank you want to see him.